There has been a collision a number of cars on the main road to town.
A) engaging B) composing C) involving D) consisting
选involving
第1题:
A.Has-arelationshipsshouldneverbeencapsulated.
B.Has-arelationshipsshouldbeimplementedusinginheritance.
C.Has-arelationshipscanbeimplementedusinginstancevariables.
D.Is-arelationshipscanbeimplementedusingtheextendskeyword.
E.Is-arelationshipscanbeimplementedusingtheimplementskeyword.
F.Anarrayoracollectioncanbeusedtoimplementaone-to-manyhas-arelationship.
G.TherelationshipbetweenMovieandActressisanexampleofanis-arelationship.
第2题:
A. Crosstalk
B. Broadcast storm
C. Duplex mismatch
D. Collision
第3题:
第4题:
He is talking so much about America as if he ____ there.
A、had been
B、has been
C、was
D、been
第5题:
第6题:
将students中的列变量重新命名为: (1)id_number, name, gender, score, has_graduate (2)选出Bob的性别gender,并存入变量bob_gender (3)选出列has_graduate,并存入向量status (4)创建数据框part_df,其中包含前三个学生的所有信息 (5)创建数据框rest_df,包含其余学生的所有信息