A.The first man on Mars
B.Human adaptation to space
C.What makes a good astronaut?
D.Difficulties encountered by Yuri Gagarin

A.higher
B.bigger
C.greater
D.larger

A.who
B.when
C.that
D.whose

A.make
B.have
C.give
D.bring

A.therefore
B.thus
C.however
D.instead

A.number
B.each
C.amount
D.few

A.number
B.each
C.amount
D.few

A.I’ll think about that.
B.I don’t agree.
C.I don’t think so.
D.I can’t agree more.

A.That sounds like fun.
B.Yes, it is certainly.
C.No, have you?
D.Not really.

A.That sounds like fun.
B.Yes, it is certainly.
C.No, have you?
D.Not really.