They started off at about 5 o’clock in the morning . They should       there by now .

A．arrive

B．have been arriving

C．have arrived

D．be arriving

在确定现金及现金等价物的数额时，可以参考相当于家庭每月支出（）的额度。

A.l~4倍

B.3~6倍

C.5~8倍

D.7~10倍