—Why, my new computer is rubbish! Five hours has passed and it still hasn’t finished the downloading.

—Don’t worry. You know, sometimes the Internet ________ be very slow.

A．can

B．may

C．should

D．must

执行保障措施在当事人到期不缴纳罚款的情况下，行政机关可以采取每日按罚款数额的（）加处罚款。

A.0.5%

B.1%

C.2%

D.3%