在编制循环图表时，为了防止实际工作中不可遇见的事故及短时间停工而打乱循环作业应考虑（）的备用时间在内。

A．5%

B．10%

C．15%

D．20%

Peter went to a concert _______ his favourite band played and sang.

A．which

B．for which

C．at which

D．in which