通常要求室内走线架的高度为(),宽度为().
A.2200mm,300mm
B.2400mm,400mm
C.2600mm,400mm
D.2800mm,450mm
参考答案:B
期货交易所中由集合竞价产生的价格是( )。
A.最高价 B.最低价C.开盘价和收盘价 D.最高价和最低价
The boy()to school already.
A.has taken
B.has been taking
C.is taken
D.has been taken