题目

苯酚具有微弱的酸性，能使紫色的石蕊试液( )A.变红色                            B.变蓝色C.变黄色                            D.不变色 答案：D解析：苯酚的酸性非常弱，不能使紫色石蕊溶液变色—Does Bob often play computer games online? —No. ________. He doesn’t have a computer.A. neverB. sometimesC. usuallyD. always