Investigators have not yet _______ the cause of the air crash.A. determinedB. exploredC. devisedD. hastened

题目
Investigators have not yet _______ the cause of the air crash.

A. determined

B. explored

C. devised

D. hastened

相似考题

1.Have they decided on the ______ of the new building yet?A. locateB. localC. locatedD. location

2.We ( ) on it for many hours but we have not yet reached any conclusion.A、have had workedB、have been workingC、are workingD、work

3.Air pollutionPeople and air pollution are often in the same places. This means that cities with large populations have the biggest problem of dirty air. Air pollution is caused by many different things. A major kind of air pollution is the gas from cars. Statistics(统计资料) show that 93 percent of all auto trips are within cities.Another major kind of dirty air is the burning of coal and oil for energy. This energy is needed to make electricity. Of course, much more electricity is used in the city than in the county.On the average, we throw away more rubbish than the year before. The burning of rubbish makes air pollution even worse. Many major industries are also responsible for the dirty air in the around cities. The fumes(烟)from iron, steel, chemical, and petrol production add particles(微粒)to the air.The effects of air pollution range from mild headaches to death. The levels of pollution found in heavy traffic may cause headaches for loss of clear vision. Wherever coal and oil are used for fuel, fumes may kill trees and plants and cause metal to corrode(腐蚀). In some of the larger cities, these fumes endanger the lives of human beings by contributing to lung diseases and causing early death.26. The key point of the passage is that().A. the cause of air pollution is peopleB. the causes and the effects of air pollution are both found in citiesC. the effects of air pollution range from headaches to death27. What is the purpose of this passage?A. to persuade people to stop polluting the air().B. to tell the causes of air pollutionC. to tell why cities are bad places to live28. Why is air pollution more grave in the city than in the country?().A. Because there are larger populations in cities.B. Because the air in the city is dirty.C. Because there are much more gas fumes from cars and burning of coal and oil for energy in the city than in the country.29. The fumes from coal and oil may cause metal().A. to corrodeB. to twistC. to turn black30. In larger cities, the fumes from coal and oil may contribute to().A. heart diseaseB. loss of clear visionC. lung diseases

4.I _____my breakfast at 8, but_____ I lunch yet. .A. had, haven't hadB. had, didn't haveC. have had, didn't have

更多“Investigators have not yet _______ the cause of the air crash. A. determinedB. exploredC. devisedD. hastened”相关问题

  • 第1题：

    Have you checked()at the hotel yet?

    A、in

    B、out

    C、up


    正确答案:A

  • 第2题：

    If the engine does start on air, but combustion does not immediately begin, the cause may be _____.

    A.failure of the fuel pumps

    B.starting air pressure too low

    C.stop valve in air line closed

    D.the turning gear still engaged


    正确答案：D

  • 第3题：

    __________enough time and money, the investigators would have been able to discover more evidence in this case.

    A．Giving
    B．Given
    C．To give
    D．Being given

    答案：B
    解析：
    考查非谓语动词。investigators和give之间是被动关系。故用过去分词形式作条件状语．相当于If(the investigators were)given…。句意为“如果给调查者足够的时间和资金．他们就可以在这个案子中发现更多的证据了”．

  • 第4题：

    If headaches only occur at night,lack of fresh air is often the cause.

    A:start
    B:begin
    C:happen
    D:visit

    答案：C
    解析：

  • 第5题：

    Have you installed the new software?（）

    • A、Installed. 
    • B、Uninstalled.
    • C、No, not yet. 
    • D、Yes, not yet.

    正确答案:C

  • 第6题：

    单选题
    The text suggests that investigators of monkeys’ social behavior have been especially interested in aggressive behavior among monkeys because ______.
    A

    aggression is the most common social behavior among monkeys

    B

    successful competition for incentives determines the social order in a monkey group

    C

    situation that elicit aggressive behavior can be studied in a laboratory

    D

    most monkeys are potentially aggressive, yet they live in social units that could not function without control of their aggressive impulses


    正确答案： C
    解析：
    细节题。文章第一段最后一句提到“Studies directed at describing aggressive behavior and the situations that elicit it…were therefore among the first investigations of monkeys’ social behavior”，由therefore可知前面既是研究人员选择研究该项目的原因，文章首句提到“Investigators of monkey’s social behavior have always been struck by monkeys’ aggressive potential and the consequent need for social control of their aggressive behavior”，对应选项D，故D项为正确答案。

  • 第7题：

    单选题
    Which of the following may cause that an engine doesnt turn on starting air?（）
    A

    too low starting air pressure

    B

    main starting valve closed

    C

    neither A nor B

    D

    A and B


    正确答案： B
    解析： 暂无解析

  • 第8题：

    单选题
    Which of the following problems could cause air to blow out through the inlet air filter of a running compressor?（）
    A

    Excessive compression in the cylinder

    B

    A broken intake valve

    C

    A dirty inlet filter element

    D

    An improperly adjusted discharge valve


    正确答案： B
    解析： 暂无解析

  • 第9题：

    单选题
    _____
    A

    Many people died in a fire.

    B

    Two persons were injured.

    C

    There was a traffic accident.

    D

    There was an air crash.


    正确答案： B
    解析：
    细节题。由女士的回答“the bus accident last night”可知，昨晚发生了一起交通事故，正确答案为C。
    【录音原文】
    M: Did you hear about the bus accident last night?
    W: Yes. It was terrible. Five people were injured.
    Q: What happened last night?

  • 第10题：

    单选题
    Exhaust temperature increases in all cylinders, the possible cause may be（） (1) increased scavenging air temperature (2) air in fuel pumps and fuel valves (3) fouling of air and gas passages
    A

    (1)+(2)

    B

    (1)+(3)

    C

    (2)+(3)

    D

    (1)+(2)+(3)


    正确答案： B
    解析： 暂无解析

  • 第11题：

    单选题
    When starting air is admitted, a diesel engine turns over very slowly without firingThe cause may be （）
    A

    an obstruction in an cylinder

    B

    water accumulation in some engine cylinders

    C

    low starting air pressure

    D

    low scavenge air pressure


    正确答案： A
    解析： 暂无解析

  • 第12题：

    单选题
    If the engine does start on air, but combustion does not immediately begin, the cause may be （）.
    A

    failure of the fuel pumps

    B

    starting air pressure too low

    C

    stop valve in air line closed

    D

    the turning gear still engaged


    正确答案： C
    解析： 暂无解析

  • 第13题：

    There are only a few ________ from the air crash.

    A.survive

    B.survivors

    C.survival

    D.survivor


    正确答案：B

  • 第14题：

    What is the most probable cause of reduced capacity in a reciprocating air compressor ________．

    A.Carbon on cylinder heads

    B.Faulty unloader

    C.Leaking air valves

    D.Plugged air cooler


    正确答案：C

  • 第15题：

    If headaches only occur at night,lack of fresh air is often the cause.

    A:start
    B:begin
    C:happen
    D:visit

    答案：C
    解析：

  • 第16题：

    Have you installed the new software?（）

    AInstalled. 

    BUninstalled.

    CNo, not yet. 

    DYes, not yet.


    C
    略

  • 第17题：

    单选题
    Broken valve strips in an operating low pressure, air compressor will cause （）.
    A

    an immediate crankcase explosion

    B

    oil contamination in the compressed air

    C

    a decrease in compressor capacity

    D

    no immediate loss of the compressed air capacity


    正确答案： B
    解析： 暂无解析

  • 第18题：

    单选题
    Air bubbles in a hydraulic governor can cause （）
    A

    sluggish response

    B

    speed droop variations

    C

    isochronous governing

    D

    sensitivity increase


    正确答案： A
    解析： 暂无解析

  • 第19题：

    单选题
    Which cause of the following can lead to the engine not to start on air?（）
    A

    starting air pressure too high

    B

    correct timing of starting air valves

    C

    three of the starting valves stuck

    D

    the turning gear disengaged


    正确答案： A
    解析： 暂无解析

  • 第20题：

    单选题
    If over a period of weeks the air-box pressure of a turbo-charged, diesel engine, operating at full load, appears to be dropping off, the cause can be （）.
    A

    open air-box drains

    B

    loss of cooling water to the diffuser

    C

    gradual fouling of the air filters

    D

    improperly timed exhaust valves


    正确答案： A
    解析： 暂无解析

  • 第21题：

    单选题
    In context, which version of the underlined part of sentence 3 (reproduced below) is the best?Baby lobsters are preyed on by fish and crabs because they don't have a hard shell yet and can't defend themselves with fierce claws yet.
    A

    the lobsters still lack both hard shells and fierce claws with which to fend off predator

    B

    the lobsters cannot attack their fish and crab predators with fierce claws or fend their predators off with a hard shell

    C

    they don't have a hard shell yet and can't defend themselves with fierce claws yet

    D

    the lobsters don't have a hard shell and can't yet defend themselves with fierce claws

    E

    the fish and crabs do not have hard shells or fierce claws yet


    正确答案： B
    解析：
    原句中“they”的指代不明，且“yet”的使用造成重复。A项纠正了这些错误且使得句子的表述很清晰。

  • 第22题：

    单选题
    Disastrous explosions have been caused by accumulations of oil or oil vapour in air lines not drainedAccording to the above sentence, which of the following statements is true?（）
    A

    Oil vapour in air piping are dangerous

    B

    Explosion will cause oil vapouring in air lines

    C

    Oil vapour in air piping should be drained

    D

    Oil in air piping should not be drained


    正确答案： C
    解析： 暂无解析

  • 第23题：

    单选题
    Unless the conservator can find a way to protect the photographs in the archives from light and air, these precious historical documents have deteriorated and will continue to do so both in color and in fine detail.
    A

    have deteriorated and will continue to do so

    B

    will continue to deteriorate

    C

    have been and will continue to deteriorate

    D

    will continue to deteriorate, as they already have,

    E

    will be deteriorating yet more


    正确答案： E
    解析：
    A、C、D三项的表述与句意不符；E项不符合习惯表达，故本题应选B项。

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