【C7】
A. similar
B. identical
C. diverse
D. differential
【C20】
A. source
B. origin
C. resource
D. base
A.Four years.B.Five years.C.Three years.D.Six years.
A. Four years.
B. Five years.
C. Three years.
D. Six years.
【C19】
A. put
B. keep
C. come
D. catch