[单项选择]Whether there is sufficient nitrogen on Mars is important because it ______.


A. can raise the temperature of Mars
B. can protect living beings from harmful rays
C. can change the atmosphere of Mars
D. is an important part of the air people breathe

[单项选择]Whether there is sufficient nitrogen on Mars is important because it ______.


A. can raise the temperature of Mars
B. can protect living beings from harmful rays
C. can change the atmosphere of Mars
D. is an important part of the air people breathe

[单项选择]When will people probably be able to live on Mars


A. In 200 years.
B. In 10,000 years.
C. In 100,000 years.
D. Unknown.

[单项选择]This information is not sufficient by itself to prove your argument but it may be used as __________. evidence.


A. subtle
B. subsidiary
C. substantial
D. subjective

[单项选择]He has sufficient time to finish the task.
A. perfect
B. adequate
C. great
D. limited

[单项选择]According to the Mars Theory, why does the moon contain little iron

[单项选择]Scientists are interested in Mars because ______.


A. people might have to migrate there someday
B. people could live there naturally
C. life has ever existed there
D. its atmosphere is quite different

[单项选择]you got Ul5 late won't be a sufficient excuse for your being late for class（）
A. It is
B. That
C. Because
D. What

[单项选择]（）you got up late won' t be a sufficient excuse for your being late for class.
A. It is
B. That
C. Because
D. What

[单项选择]She sometimes asked herself the question whether it was_________ the effort.


A. worthy
B. worthwhile
C. worth
D. worthless

[单项选择]

To determine whether or not the employee correctly understands the message, the project manager needs to （）.

A. reduce the filtering
B. eliminate barriers
C. obtain feedback
D. use more than one medium

[单项选择]The designer himself is not sure whether this software is appropriate（）children under 12 years old.
A. with
B. in
C. for
D. of

[单项选择]

Parents with an adopted child wonder whether, when and how to tell their child that he or she is adopted. They also want to know if there are special problems for an adopted child.
Child and adolescent psychiatrists (精神病学家) recommend that the child be told about the adoption by the adoptive parents. Children should be told about their adoption in a way that they can understand.
There are two different views on when a child should be told about the adoption. Many experts believe the child should be told at the earliest age possible. This approach provides the child an early opportunity to accept and integrate the concept of being "adopted". Other experts believe that telling a child too early may confuse the young child who can’t really understand the event. These experts ad vise waiting until the child is older.
In either case, children should learn of their adoption from the adoptive parents. This helps give the message that adopti
A. learn more about their adoption from the adoptive parents
B. read mere children's story books about adoption
C. stay at home because they think the adoption is shameful or bad
D. talk about it with other people such as neighbors