已知⊙O1的半径为3cm，⊙O2的半径为5cm，圆心距O1O2 为2cm，则⊙O1和⊙O2的位置关系是 （ ） A. 相交 B. 外离 C. 外切
单词拼写 (共10小题; 每小题1分,满分10分) 1. When I saw her in the street, I stopped and smiled, but she i___________ me and walked on. 2. Judging from his accent, he is a n_________ of Ni
依次填入下面句子中横线上的词语恰当的一项是2006年4月，访问美国，向全世界传达了这样一种信息：国际 、国内 、两岸是中国当前所需要努力的方向
28. Yellow Mountain is such an attractive place of interest everyone likes to visit. A. as B. that C. which D. what
右图为某原电池装置： （1）若A为Zn，B为石墨，电解质溶液为稀硫酸，则A极的电极反应式为______________________________。 （2）若A为铜，B为铁，电解质溶液
水是重要的物质，在实验室中常用于溶解物质、配制溶液． （1）向50mL水（密度为1g/mL）中溶解一定量KNO3固体的操作如下，请根据如图实验现象和溶解
如图17-3-5所示电路，一电感线圈和一个“220 V40 W”的灯泡串联，电路两端接在220 V的交变电路中.如果将电感线圈的铁芯抽去，则灯泡的发光情况是______
The people here try to collect_______ in dry season. A. as many rain as they can B. as much rain as they can C. as much rains as they can D. as many rains as they can
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