A、 π/4
B、 π/2
C、 π
D、 2π
答案:C
A、 π/4
B、 π/2
C、 π
D、 2π
答案:C
A. so
B. and
C. or
D. but
A. can
B. may
C. need
D. must
A. relationship
B. agreement
C. environment
D. investment
A. How slow
B. How fast
C. What a slow
D. What a fast
A. can
B. must
C. may
D. need
A. is read
B. are read
C. reads
D. were read
A. in trouble
B. in style
C. in order
D. /
A. save
B. saving
C. saved
D. to save
A. sad
B. sadness
C. saddest
D. sadly
A. thankful
B. more thankful
C. most thankful
D. less thankful