题型:选择题 一定温度下恒容的密闭容器中,反应A2(g)+B2(g)═2AB(g)达到平衡的标志是( )A.单位时间内生成nmolA2的同时生成nmolABB.容器内气体的总压强不随时间变化C.单位时间内生成2nmolAB的同时生成nmolB2D.容器内气体的平均相对分子质量不随时间变化 查看答案
题型:选择题 A large crowd _______ wildly as the pilot _________ her plane safely in California.A.had cheered; was landingB.had cheered; landedC.was cheering; had landedD.was cheering; landed 查看答案