液压助力器上用于控制动作筒运动的液压活门是:().A.液压伺服活门。 B.三位四通选 发布时间:2019-11-12 06:19 │ 来源:www.tikuol.com 题型:单项选择题 问题: 液压助力器上用于控制动作筒运动的液压活门是:().A.液压伺服活门。B.三位四通选择活门。C.定压接通活门。D.减压活门。
题型:单项选择题 What do you think of the set of popular science books?-- It couldn't be better! It ______ many problems we are interested in exploring.[ ]A. covers B. consults C. measures D. writes 查看答案