发动机燃油泵通常有：（）.
A.液压泵和电动泵
B.增压级和主级泵
C.仅有增压级
D.仅有主级
参考答案：B
My aunt isn't here. She _____ Shanghai on business. She will be back in three days. [ ]
A. went
B. has gone to
C. has been to
D. will go to
佛教传入我国后的第一座庙宇是洛阳的（）
