[单项选择]Some metals are better conductors of electricity than others,______ means that the former has atoms that contain more free electrons than the latter.
A. that
B. this
C. it
D. which

[单项选择]Some metals are better conductors of electricity than others,______ means that the former has atoms that contain more free electrons than the latter.
A. that
B. this
C. it
D. which

[单项选择]Before you conduct a survey, you' d better refer to certain books.
A. career
B. holiday
C. plan
D. research

[单项选择]Some hard plastics can be______ metals in manufacturing machine parts.
A. substituted for
B. taken the place of
C. replaced in
D. given way to

[单项选择]Some hard plastics can be ______ metals in manufacturing machine parts.


A. substituted for
B. taken the place of
C. replaced in
D. given way to

[单项选择]

Passage Four
Sometimes teens need to have some time away from their families. They may want’ to move out of the family home for a while.
Many parents will say no to this demand. But experts say it might be a good idea to let your teens live with a friend or relative.
"It was the break I needed at the time," said Richard Lerner. He is talking about the time he spent living with his grandmother when he was 15.
"It allowed me to be a different person than I was with my parents." Lerner said. He now heads the Institute for Children, Youth and Families at Michigan State University.
Experts say teens living away from their families can test new ways of thinking and getting along with people. They may see new solutions (解答) to problems.
This is different from running away, the experts stress. Runaways are often fleeing serious problems.
Some teens who want some time away from family attend a structu
A. built
B. stuck
C. organized
D. drunk

[单项选择]Nowhere else in the world ______ any better food than what we have served here.
A. one will find
B. can one find
C. one has found
D. to have been found

[单项选择]______, we'd better make some changes in the plan.
A. That is the case
B. That been the case
C. That to be the case
D. That being the case

[单项选择]For some people, it may be better
A. to wear a seat belt for health reasons.
B. not to wear a seat belt for health reasons.
C. to get a valid medical certificate before wearing a seat belt.
D. to pay a fine rather than wear a seat belt.

[单项选择]Why do some people think hemp is better than trees for paper industry
A. It is cheaper to grow hemp than to cut down trees.
B. More paper can be produced from the same area of land.
C. Hemp planting can beautify the environment.
D. Hemp can produce paper of high quality.