对易挥发和易燃的有机溶剂，应采用（）或其它加热方法。
参考答案：水浴
正六边形的内角和为 _________ 度．
--- What on earth did the manager want to know, Jim?
--- ____ that we could finish the project.
A．What it was
B．What was it
C．When was it
D．When it was
