控制区
A.18~28℃B.18~25℃C.18~24℃D.20~24℃E.20~25℃
参考答案:A
I am listening to music________ my sister is doing her homework.[ ]
A. when
B. while
C. and
D. so
大豆提油套利是大豆加工商在市场价格关系基本正常时进行的。( )