根据句意,用括号中所给单词的适当形式或句子的语法要求填空。 1. Playing too many computer games is ▲ (harm) to you. 2. We should speak to the old man ▲ (polite). 3. —How many ▲ (tooth) does a dog have? —Sorry, I have no idea.Let’s search on the Internet. 4. A computer is ▲ (expensive) than a TV set. 5. Have you read ▲ (today) newspaper? 6. I ▲ (not go) to bed until my mother came back at ten last night. 7. You need ▲ (return) t在下列物质转化中,A是一种酸式盐,D的相对分子质量比C的相对分子质量大16,E是酸,当X无论是强酸还是强碱时,都有如下的转化关系:ABCDE。当X是强酸时,A、B、C、D、E均含同一种元素;当X是强碱时,A、B、C、D、E均含另外同一种元素。请回答:(1)A是________,Z是________。(2)当X是强酸时,写出B生成C的化学方程式________。(3)当X是强碱时,E是________,写出E和铜反应生成C的化学方程式_____。