有关普通玻璃的叙述，错误的是 A.玻璃是混合物B.制玻璃的原料是纯碱、石灰石、石英、粘土C.玻璃不是
已知函数f(x)=，x∈，则满足f(x0)＞f()的x0的取值范围为 ▲ ．
阅读“城市水循环示意图”和“城市化前后的水文过程曲线图”，分析完成下列问题。（1）①是城市化_____________水文过程曲线；②是城市化_______________
We thought it was he who did it, but it _________ that he wasn’t even there. A. turned up B. turned down C. turned off D. turned out
阅读下列短文，回答短文后的问题．在探究“滑动摩擦力的大小跟哪些因素有关”的过程中，一些同学作出了以下猜想：猜想A 滑动摩擦力的大小可能与
（7）某地区有300家商店，其中大型商店有30家，中型商店有75家，小型商店有195家，为了掌握各商店的营业情况，要从中抽取一个容量为20的样本，若采
一个塑料瓶装有500ml水，则所装水的质量为＿＿＿＿g，把它放置在太阳底下1小时后，水温由10℃升至30℃，水吸收的热量为＿＿＿＿J。
One day a student went to see his teacher. He had been given an important position and now was coming to say goodbye to his teacher. The old man asked him how he would live among high officials. The s
、
为相反数，
、
为倒数，
，则
