题型:选择题 东东的氢气球不小心脱手升到了空中。以下关于气球上升过程中的分析,正确的是 [ ]A. 随高度增加,大气压增大,气球体积减小 B. 随高度增加,大气压增大,气球体积增大 C. 随高度增加,大气压减小,气球体积增大 D. 随高度增加,大气压减小,气球体积减小 查看答案
题型:选择题 This is the last time that we _____ late for class. [ ]A .had been B. are C. were D. have been 查看答案