6.
We are talking about the preservation of ____________ resources.
A. natural
B. naturally
C. nature
D. naturalize
7.
Mrs Mi suggests ___________ showers to save money.
A. takes
B. taking
C. should take
D. take
8.
The south Vietnam was completely liberated ___________ April 30th, 1975.
A. in
B. on
C. at
D. to
9.
Do you know the name of the man ___________ we talked about last night.
A. which
B. where
C. whose
D. whom
10.
I haven't got a passport, __________ means I can't leave my country.
A. which
B. that
C. who
D. what