爆破器材公路运输时,前后车辆应保持适当的安全距离,一般应大于()m。A、50 B、60 发布时间:2018-08-09 16:08 │ 来源:www.tikuol.com 题型:单项选择题 问题: 爆破器材公路运输时,前后车辆应保持适当的安全距离,一般应大于()m。A、50B、60C、70D、100
题型:单项选择题 用所给词的适当形式填空。1. When she couldn't find her mother, she ______ (begin) to cry.2. —When did the movie ______(begin)? —It _____ (begin) about ten minutes ago.3. At the ______ (begin) of this term, we have two new ______ (woman) teachers.4. How many _______ (wheel) does a bike have ?5. He always _____ (use) this pen to write. 查看答案
题型:单项选择题 要将转化为应可选用的试剂和操作的是①加入足量的NaOH共热后,再通入足量的CO2 ② 溶解,加热后通足量的CO2③与稀H2SO4共热后加足量的NaOH ④与稀H2SO4共热后加足量的NaHCO3 A.①②B.②③C.①④D.②④ 查看答案