下列变化属于物理变化的是( ) A.石灰浆抹墙后,墙壁发硬 B.酚酞试液遇碱性溶 发布时间:2017-06-02 21:54 │ 来源:www.tikuol.com 题型:选择题 问题: 下列变化属于物理变化的是( )A.石灰浆抹墙后,墙壁发硬B.酚酞试液遇碱性溶液变为红色C.用苛性钠干燥O2、N2等D.用生石灰制熟石灰
题型:选择题 — Tom is never late for work. Why is he absent today?— Something _____ to him. [ ]A. must happen B. should have happenedC. could have happened D. must have happened 查看答案