声功率为85dB的4台机器和80dB的2台机器同时工作时,它同声功率级为()dB的1 发布时间:2017-06-27 12:16 │ 来源:www.tikuol.com 题型:单项选择题 问题: 声功率为85dB的4台机器和80dB的2台机器同时工作时,它同声功率级为()dB的1台机器工作时的情况相同。A.86B.90C.92D.94E.96
题型:单项选择题 Those books ______ in brown paper are for the kids so that the kids will not easily tear them up.A.to do withB.done upC.being done D.having done over 查看答案