The radiation amount of a mobile phone for two half-hour periods per day is equal to ______ to an X-ray for ten seconds.

A．expose

B．exposing

C．exposed

D．being exposed

存款人因设立临时机构、异地临时经营活动和注册验资，可开立临时存款账户，临时存款账户有效期最长不超过（）年。

A、2

B、1

C、3