—What were you up to when she dropped in?

—I _________ for a while and __________ some reading.

A．was playing; was going to do

B．played; did

C．had played; was going to do

D．had played; did

保证金业务按业务种类划分为信用证保证金，保函保证金、黄金交易保证金、外汇交易保证金（）

A、银行承兑汇票保证金

B、其他保证金

C、衍生金融产品保证金

D、贸易融资保证金