题型:问答题 简答题 推理是化学学习中常用的思维方法.下列推理正确的是( )A.酸能使紫色石蕊溶液变红.通入CO2后的紫色石蕊溶液变红,所以CO2是酸B.酸性溶液的pH小于7.食醋是酸性溶液,所以食醋的pH小于7C.在同一化合物中,金属元素显正价,所以非金属元素一定显负价D.溶液中有晶体析出时,溶质质量减小,所以溶质的质量分数一定减小 查看答案
题型:问答题 简答题 Which of the following statements is true according to what you have heard A.I will eat lunch very quickly.B.I will have lunch before the meeting.C.I will eat lunch at the meeting.D.I will eat lunch while jogging. 查看答案