不属于病毒复制周期的为（）
A.脱壳
B.吸附与穿入
C.生物合成
D.扩散
E.装配与释放
参考答案：D
美国和中国香港证券市场采用的滚动交收周期分别为T+3和T+2。( )
The volunteers were so kind that they devoted most of the time _____ the disabled. [ ]
A. to help
B. helped
C. helping
D. to helping
