问题
选择题
（2011年湖南怀化，21题）已知某硫的氧化物中硫元素和氧元素的质量比为2︰3，则该硫的氧化物的相对分子质量是
A．28
B．30
C．64
D．80
答案
答案：D
设这种氧化物的化学式为SxOy，
根据题意得：32x：16y=2：3；
则x:y=1:3；
故这种氧化物的化学式为：SO3．
则该氧化物的相对分子质量为：32+16×3=80．
故选D．
搜题请搜索小程序“爱下问搜题”
（2011年湖南怀化，21题）已知某硫的氧化物中硫元素和氧元素的质量比为2︰3，则该硫的氧化物的相对分子质量是
A．28
B．30
C．64
D．80
答案：D
设这种氧化物的化学式为SxOy，
根据题意得：32x：16y=2：3；
则x:y=1:3；
故这种氧化物的化学式为：SO3．
则该氧化物的相对分子质量为：32+16×3=80．
故选D．
| 阅读理解。 | |||||||
| |||||||
| 1. You can see _____ foreign films in Feiyang Cinema this week. | |||||||
| A. one B. two C. three D. four | |||||||
| 2. If you want to see the film which was directed by Feng Xiaogang, go to the cinema on _____ . | |||||||
| A. Monday B. Thursday C. Friday D. Saturday | |||||||
| 3. Children can pay only _____ when they want to see a film on Sunday. | |||||||
| A. 5 B. 10 C. 15 D. 20 | |||||||
| 4. You can see the film _____ on Saturday. | |||||||
| A. Troy B. Harry Potter C. A World Without Thieves D. Kungfu Hustle | |||||||
| 5. Which of the following is TRUE? | |||||||
| A. Liu Dehua acted in the film Kungfu Hustle. B. The ticket price of the four films is the same. C. All the films start after 8 o'clock in the evening. D. The four films were released (发行) in the same year. | |||||||
