生活中处处有化学，请根据所学化学知识填写下列空白：
（1）碘盐. 含氟牙膏. 高钙牛奶等物质中的“碘. 氟. 钙”是指 _________。
（2）某市区家用燃气已由煤气（主要成分是CO和H2）更换为天然气，写出它们燃烧的3个化学方程式 _________ ； _________ ； _________ ．在相同温度和压强下，气体分子数与其体积成正比．燃烧煤气的灶具如需改烧天然气，灶具的改进方法是 _________ 进风口（填“增大”或“减小”），如不作改进可能产生的不良结果是 _________。
（1）元素
（2）2CO+O2
2CO2；2H2+O2
2H2O；CH4+2O2
2H2O+CO2 ；增大 ；不能充分燃烧，生成CO气体或炭黑等大气污染物
| 完型填空 | |||
| Food is very important. Everyone needs to (1)_____ well if he or she wants to have a strong body. Our minds also needs a kind of food. This kind of food is (2)_____. We begin to get knowledge even when we are very young. Small children are (3)_____ in everything around them. They learn (4)_____ while they are watching and listening. When they are getting older, they begin to (5)_____ story books, science book and so on. When they find something new, they love to ask questions and (6)_____ to find out the answers. What is the best (7)_____ to get knowledge? If we learn (8)_____ ourselves, we will get the most knowledge. If we are (9)_____ getting answers from others and do not ask why, we will never learn well. When we study  in the right way,we will learn more and understand (10)_____. | |||
| ( )1. A. sleep ( )2. A. sport ( )3. A. interested ( )4. A. everything ( )5. A. lend ( )6. A. try ( )7. A. place ( )8. A. on ( )9. A. often ( )10.A. harder | B. read B. exercise B. interesting B. something B. read B. have B. school B. with B. always B. much | C. drink C. knowledge C. weak C. nothing C. learn C. think C. way C. to C. usually C. better | D. eat D. meat D. better D. anything D. write D. wait D. road D. by D. sometimes D. well |