Mr. Smith was so angry at all ______ Bill was doing ______ he left.

A．that; what

B．that; that

C．which; which

D．what; that

计算题：已知某测点压力值约为6MPa，当测量平稳变化压力时，应选取多大测量范围的弹簧管压力表？若要求测压误差不超过±0.6MPa，应选多大的精确度等级？