[单选题]
第59题应选：
A、Yet
B、Unless
C、Although
D、Once

[单选题]
In the eyes of the author, what happens to a scholar who shares his ideas with his colleagues?
A、He risks his ideas being stolen
B、He gains recognition for his achievement
C、He is considered as an eccentric
D、He is credited with a startling discovery

[单选题]
请在第____处填上正确答案。
A、conduct
B、produce
C、use
D、consume

[单选题]
thought
A、case
B、event
C、thing

[单选题]
Air transport companies use different planes__________.
A、in the development of air transportation
B、the earliest passenger flights were successfully operated
C、to make travel easy and pleasant for the passengers
D、to provide different services
E、the shortage of qualified pilots

F traveling by air was very cheap

[单选题]
Some comments are just inviting trouble．
A、asking for
B、keeping out of
C、getting into
D、suffering from