缩合反应(缩聚反应)
参考答案:
由数种单体,通过缩合反应形成聚合物(也称缩聚物),同时析出水、卤化物、氨及醇等低分子化合物反应称作缩合反应。
已知集合A={x|x为不超过4的自然数},用列举法表示A=______.
根据下列句子的意思及所给的汉语提示,写出空缺处单词、固定短语或固定搭配的正确形式。
1. This is our _______ (三) time to plant trees.
2. I'm not really _______ (饥饿). I'll just have an ice cream.
3. Computer is one of the greatest _______ (发明). I can't imagine life without it.
4. They _______ (同意) us on some matters yesterday afternoon.
5. Mr. Smith gave us _______ (一条) advice on how to keep healthy.