题目

下列叙述正确的是 A．NH3是极性分子，分子中N原子处在3个H原子所组成的三角形的中心 B．CCl4是非极性分子，分子中C原子处在4个Cl原子所组成的正方形的中心 C．H2O是极性分子，分子中O原子不在2个H原子所连直线的中点处 D．CO2是非极性分子，分子中C原子不在2个O原子所连直线的中点处 答案：C短文改错（共10小题；每小题1.5分，满分15分）此题要求改正所给短文中的错误。对标有题号的每一行做出判断。如无错误，在该行右边的横线上划一个勾(V)；如果有错误（每行只有一个错误)，则按下列情况改正：此行多一个词：把多余的词用斜线(／)划掉，在该行右边的横线上写出该词，并也用斜线划掉。此行缺一个词：在缺词处加一个漏字符号(∧)，在该行右边的横线上写出该加的词。此行错一个词：在错的词下划一横线，该行右边的横线上写出改正后的词。注意：原行没有错的不要改。Dear Mr. Donforth,I’m writing to ask you come to our class for a visit. I’ve    76. __________heard that you have been to Greece. In our Greece unit, we       77. __________have been learning about it’s rich culture and long history.  78. __________Since you have visited Greece several times, so I would like to  79. __________know whether you have seen the old buildings here. We have     80. _________learned a lot from the text book, but I believe you personal       81. __________experience will be a lot better. Your knowledges of Greece can 82. __________help the whole class. Could you share your experiences for       83. __________us? It will be surely exciting and rewarding. I hoped that you    84. __________think about my request and visit us as soon as possibly.               85. __________