题目

It's no use ______ a lot without doing anything. A . to talk B . talking C . to talk about D . A and C 答案：B实验室有许多药品需要密封保存，下列药品需要密封保存的原因，解释错误的是（ ）A．浓盐酸──防止挥发B．氢氧化钠──防止潮解和变质C．浓硫酸──防止吸水D．生石灰──防止氧化