A
B
C
D
第1题:
A
B
C
D
第2题:
A
B
C
D
第3题:
铰链四杆机构ABCD,如果以BC为机架(静件),当机构为双曲柄机构时,各杆的长度可为()。
第4题:
A.write, calls
B. wrote, called
C.was writing, calls
D. was writing, called
第5题:
I _____ the wrong thing. Can I use your eraser?
A. write B. wrote C. am writing D. will write