下列说法中，正确的是（ ）
A．溶于水的强电解质在水中完全电离
B．强电解质在水中溶解度一定大于弱电解质
C．强电解质一定是离子化合物
D．强电解质溶液的导电性一定大于弱电解质
A、强电解质是指在水溶液中，或熔融状态下能完全电离的化合物，即溶于水的强电解质在水中完全电离，故A正确；
B、强电解质在水中溶解度不一定大于弱电解质，如硫酸钡和醋酸的溶解度，故B错误；
C、氯化氢是强电解质，属于共价化合物，故C错误；
D、电解质溶液的导电性和自由移动离子的多少有关，和强、弱电解质之间没有必然的联系，故D错误．
故选A．
Last night I was driving from Harrisburg to Lewisburg, a distance of about 80 miles. It was late, and I was driving . At one point along an open highway, I came to a crossroad with a traffic light. I was on the road by now, but as I came near the light, it turned , and I braked to a stop. I looked left, right, and behind me. Nothing. No car, no suggestion of headlights, there I sat, waiting for the light to , the only human being, for at least a mile in any . I started wondering why I to run the light. I was not afraid of being caught, because there was no policeman anywhere around and there certainly would have been no in going through it. Much later that , after I'd met with a group in Lewisburg and had climbed into bed near midnight, the question of why I'd stopped for that light me. I think I stopped it's part of a contract(契约) we all have with each other. It's not only the law, but it's an agreement we have, and we trust each other to follow : we don't go through red lights. We do we say we'll do. We show up when we say we'll show up. I was so of myself for stopping for that red light. And as no one would ever have known what a good person I was on the road from Harrisburg to Lewisburg, I had to tell someone.
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