A、 a
B、 an
C、 the
D、 /
答案:B
A、 a
B、 an
C、 the
D、 /
答案:B
A. -1
B. 0
C. 1
D. 不存在
A. 0.5
B. -1
C. -0.5
D. 1
A. How far
B. How much
C. How often
D. How soon
A. How often
B. How soon
C. How long
D. How far
A. describes
B. improves
C. prepares
D. corrects
A. on
B. beyond
C. in
D. at
A. damaged
B. were damaged
C. were damaging
D. are damaged
A. can
B. must
C. may
D. need
A. 3∈M
B. 1∈M
C. 4∈M
D. -1∉M
A. 3∈A
B. 1∈A
C. 0∈A
D. -1∉A