在分级沉淀实验中,同种酶的纯酶溶液和粗酶溶液的分级范围相同。
参考答案:错
单词拼写与运用。
根据句意完成已给出首字母或汉语提示的单词,使补全后的句子意思通顺,语法正确。
1. September is the n________ month of the year.
2. I work in a l________. There are many books for people to read.
3. Please be q _____, the child is doing his homework.
4. We can't listen to music in the hallway, but we can listen to it o _____.
5. He is a policeman and all the_____ (小偷) don't like him.
6. Thanks for ________ (帮助)me.
7. Rose Smith can't stand the_____ (主张,想法) that old people can't be beautiful.
8. When people go to visit Xinjiang, they will taste (品尝) the _____ (特色) there.
工艺技术方案和工艺流程方案优化选择的()的基本要求是充分发挥投资效益,降低生产成本,以较少资金,获取更大效益。
A.先进适用性
B.安全可靠性
C.经济合理性
D.技术来源可得性