第1题:
第2题:
language is a product of the brain
language is a system of meaningful codes
sign language is derived from natural language
sign language is as efficient as any other language
第3题:
The world population is increasing faster and faster.
Half of the world’s water resources have been seriously polluted.
Humanity has not placed sufficient value on water resources.
Only half of the world’s water can be used.
第4题:
第5题:
第6题:
第7题:
第8题:
第9题:
第10题:
第11题:
第12题:
Some are built underground.
Some can be eaten.
Most are sewed with grasses.
Most are dried by the sun.
第13题:
How to render automobiles pollution-free.
How to make smaller and safer automobiles.
How to solve the problem of traffic jams.
How to develop an automated subway system.
第14题:
第15题:
第16题:
第17题:
第18题:
第19题:
第20题:
第21题:
relies on the social welfare system which support them
has much to do with the amount of support they get from others
depends on their ability to deal with daily worries and troubles
is closely related to their strength for coping with major changes in their lives
第22题:
第23题:
第24题: