A:ab=1
B:a+b=0
C:a﹣b=0
D:a2=b2
工厂中,贾师傅每天生产10个零件,李师傅每天生产20零件,现需要300个零件。若全由贾师傅生产,a天后可以完成,列出等量关系式为____。
⑴____A. library B. big C. classroom
⑵____A. left B. right C. show
⑶____A. near B. street C. far
⑷____A. zoo B. school C. me
⑸____A. help B. am C. is