问题
选择题
下列物质中，酸性最强的是
| 选项 | A | B | C | D |
| 物质 | 冷酸灵牙膏 | 自制肥皂水 | 威猛洁厕灵 | 美之源果粒橙 |
| pH | 7.9 | 11.5 | 0 | 3.6 |
答案
答案：C
题目分析：pH值零到七为酸性，七为中性，七到十四为碱性，值越小酸性越强，所以威猛洁厕灵酸性最强。
点评：考察生活中常见物质的pH值，较简单，但是却是中考中的必考题，平时注意积累总结。
搜题请搜索小程序“爱下问搜题”
下列物质中，酸性最强的是
| 选项 | A | B | C | D |
| 物质 | 冷酸灵牙膏 | 自制肥皂水 | 威猛洁厕灵 | 美之源果粒橙 |
| pH | 7.9 | 11.5 | 0 | 3.6 |
答案：C
题目分析：pH值零到七为酸性，七为中性，七到十四为碱性，值越小酸性越强，所以威猛洁厕灵酸性最强。
点评：考察生活中常见物质的pH值，较简单，但是却是中考中的必考题，平时注意积累总结。
| 阅读理解。 |
| When you run downhill, gravity pulls you. When you throw a ball up, gravity pulls it down. When you sit, gravity holds you down. When you lie down, gravity holds you to the bed. We know gravity is everywhere even though we can't see it.We know it pulls on every stone and every drop of water. It pulls on everything. The gravity of the earth pulls everything towards the center of the earth.You know this when you try to lift a heavy stone. Gravity pulls it down. The more the stone weights, the more gravity pulls on it. To lift the stone, you must pull up harder than gravity pulls down. The earth has gravity and the moon also has gravity. The moon has less gravity than the earth has. This means the moon's gravity does not pull as hard as the earth's gravity. Do you weigh 60 kilograms? That means the pull of the earth's gravity on you is 60 kilograms. If you were on the moon, you would weigh only 10 kilograms. The pull of the moon's gravity on you would be only 10 kilograms. |
| 1. The word "gravity" in the passage means "______" in Chinese. |
[ ] |
A. 物体质量 |
| 2. Gravity ______. |
[ ] |
| A. pulls on everything high up B. is everywhere C. can be seen everywhere D. pushes on everything |
| 3. You can't lift up a big stone because ______. |
[ ] |
| A. more gravity pulls it down B. you don't know how to do it C. you are not strong D. gravity is out of the stone |
| 4. If you weigh 50 kilograms, that means ______. |
[ ] |
| A. you can lift up 50 kilograms of things B. the earth's gravity on you is less than 50 kilograms C. you can lift up more than 50 kilograms of things D. the earth's gravity on you is 50 kilograms |
| 5. If a stone weighs four kilograms on the moon, it weighs . |
[ ] |
| A. 10 B. 24 C. 40 D. 60 |