用下列概念填空（填序号）：①单质，②化合物，③纯净物、④混合物、⑤氧化物．
（1）天然水经过沉淀、过滤、吸附、消毒后属于______；
（2）含有氢、氧元素的物质可能是______，肯定不是______；
（3）高锰酸钾含有钾元素、锰元素、氧元素，应属于______．
（1）天然水经过沉淀、过滤、吸附、消毒后仍然含有一些可溶性物质，属于混合物．故填：④．
（2）含有氢、氧元素的物质可能是化合物，如水．可能是纯净物，如水．可能是混合物，如空气．可能是氧化物，如水．不可能是单质，因为单质中只有一种元素．故填：②③④⑤；①．
（3）高锰酸钾是含有钾元素、锰元素、氧元素的纯净物，属于化合物．故填②．
| 完形填空。 |
| Mr. Brown, a teacher in a primary school, often fell asleep in class, but he didn't want his 1 to know and do that. One day he again fell asleep 2 . When he woke up, one of the 3 , Tom, asked him, "Why did you fall asleep in class just now, dear sir?" Mr. Brown's face turned 4 . "I…I…The Sungod (太阳) asked me to visit him in my dream." he said. Tom wanted to say something, 5 he said nothing. The next day, Tom also 6 in class. When the teacher saw him, he 7 Tom up and asked him, "Why did you fall asleep in class and not 8 me, Tom?" Tom answered with a smile on his 9 , "The Sungod asked me to visit him, too." The teacher became 10 when he heard this and asked, "What did he say to you, then?" He told me he didn't see you yesterday. |
| ( )1. A. teachers ( )2. A. at table ( )3. A. boys ( )4. A. black ( )5. A. but ( )6. A. went to bed ( )7. A. woke ( )8. A. hear from ( )9. A. head ( )10. A. angry | B. students B. in class B. girls B. red B. and B. got up B. threw B. hear of B. nose B. happy | C. parents C. in hospital C. men C. yellow C. or C. fell asleep C. hung C. listen to C. face C. sad | D. workers D. in bed D. women D. green D. so D. went to work D. brought D. look at D. ear D. pleased |