制备碘溶液时加入碘化钾的作用是
A．增溶
B．补钾
C．助溶
D．增加离子强度
E．防止碘挥发
参考答案：C
_________ green or _________ in a light green room _________ good for us.
A．Wear; sleep; is
B．Wearing; sleeping; are
C．Wear; sleep; are
D．Wearing; sleeping; is
外汇买卖双方在成交后的7个营业日内办理交割手续的外汇交易方式称为现汇交易。 ( )
