The abacus invented in the sixth century by Chinese people. A. be B. is C. was D. were 查看更多

 

题目列表(包括答案和解析)

The abacus _____ invented in the sixth century by Chinese people.
[     ]
A. be
B. is
C. was
D. were

查看答案和解析>>


同步练习册答案