多云的夜晚比晴朗的夜晚较为温暖，这是因为（ ） A.多云的白天地面辐射强烈 B.多云的白天大气辐射微弱 C.多云的夜晚地面热量
It was a dark and cold night. The car driver didn’t have even one passenger all day. When he went by the railway station, he saw a young man coming out with two bags in his hands. So he quickly open
You think you’re poor, but look at people in really poor countries—it’s all ____． A．relative B．simple C．similar D．related
函数在处的切线方程是（ ） A． B． C． D．
_____ the Internet is making people closer, it may also be breaking some homes or will cause other family problems. A. When B. If C. As D. While
与一对平行线5x－2y－6＝0,10x－4y＋3＝0等距离的点的轨迹方程是( ) A．20x－8y－9＝0 B．10x－4y－5＝0 C．5x－2y－3＝0
氯气是一种重要的工业原料。工业上利用反应在3Cl2＋2NH3＝N2＋6HCl检查氯气管道是否漏气。下列说法错误的是（ ） A．若管道漏气遇氨就会产生白烟
古人云：奢糜之始，危亡之渐。这句话体现的哲学道理是（ ） ①现象是本质的外部表现 ②特殊性中包含着普遍性 ③量变是质变的必要准
