A: 1,3,4-三甲苯
B: 2-甲基-2-氯丙烷
C: 2-甲基-1-丙醇
D: 2-甲基-3-丁炔
下列反应中,既属于氧化反应又属于化合反应的是____
A.CH4+2O2CO2+2H2O B.2H2+O22H2O
C.Na2CO3+Ca(OH)2═CaCO3↓+2NaOH D.____ .
用显微镜观察切片时,由低倍镜换成高倍镜后,观察到的物像与原物像相比( )
根据表格内容,回答问题。
Paul
I have been a volunteer as a French teacher for three months and it was a great experience to teach French. I really enjoyed it and I also improved my French.
Helen
During my college days, I joined a group called ROS (Reaching Out Society). We provide children and older people with food. It feels great to help other people. And now, I often give food to the homeless people in the street.
Mike
I'm volunteering at an animal shelter (动物收容所) that's just for cats. I feed the cats and play with them. It's very fun. I was also volunteer at a hospital for a little more than 2 years. I answered phone calls, looked after patients and helped nurses. I did some cleaning too.
Marian
I did volunteer work to graduate from high school. It was a requirement(资格). I volunteered at a school for disabled kids. I played basketball and other sports with them and served food and drinks. It was actually pretty cool. If I weren't so busy now, I'd do it again.