（）不做铜片腐蚀试验。
A、汽油
B、柴油
C、润滑油
D、重质液体石蜡
参考答案：D
—English has a large vocabulary, hasn’t it?
—Yes. ________ more words and expressions and you’ll find it easier to read and communicate.
A．Know
B．Knowing
C．To know
D．Known
凝结水输送泵的型号及主要参数是什么？
