Miss Li _____as a secretary for five years in the company,and now she is a general manager of it.

A．serves

B．served

C．had served

D．has served

因为量取液体的体积与量筒规格相差越大，准确度越小，所以试验中应根据所取溶液的体积，尽量选用能一次量取的（）规格的量筒。

A、最大

B、最小

C、最多

D、最少