在正向市场中,如果市场行情下滑,远期月份合约对近期月份合约升水可以大于与近期月份合约间相差的持仓费。()
参考答案:错
Jimmy was so nervous not a single word _____ down in the dictation.
A.he wrote
B.he was written
C.did he write
D.was he written
地球上最早的细胞大约出现在()亿年。
A.4一8
B.8-12
C.20-23
D.36-38