题干

下列各组粒子,属于同种核素的是  ____ (填编号,下同),互为同位素的是  ____ ,互为同素异形体的是  ____ ,互为同分异构体的是  ____ .
①16O2和18O3 ②质子数相同而中子数不同的两种粒子
③11H、D、T    ④1530R和(核内15个中子)
⑤葡萄糖和果糖     ⑥
上一题 下一题 0.0难度 选择题 更新时间:2018-01-19 03:11:02

答案(点此获取答案解析)

④,③,①,⑤

同类题1

信息匹配。

School BBS   About life in England

A: Many English people live in houses, not in apartments. Most houses have gardens. Many young people don't live with their parents.

B: School starts at about nine o'clock in the morning and finishes at about three o'clock in the afternoon. All the children go to school when they are four or five years old.

C: Most office workers start to work at about nine in the morning, and finish work at about five or six in the afternoon. Most people don't go home for lunch, and they just have a quick meal!

D: Most shops open at about nine o'clock in the morning and close at about eight o'clock in the evening. People can buy fast food or life things in the shops.

E: In the evenings, I usually do my homework before watching TV. Mum helps me with my homework. My family like to watch Coronation Street (an English soap opera).

F: The second most popular activity in England is visiting friends or relatives. Mum and Dad go out and visit friends at least once a week.

①They usually go to work by bus, and they work with computers. ____

②I have to help Mum wash the dishes after meals. I also have to clean my bedroom. ____

③On weekends, many families go to the open market. People sell vegetables, clothes, toys, and anything else out on the street. ____

④Most families have a car, a computer, a washing machine, etc. Almost everyone has a mobile phone. ____

⑤Most children take a lunch box to school. There are usually things like sandwiches, fruit and a bag of French fries in it. ____

同类题4

完形填空

    In February of 2005, Phil Belfiore was teaching one of Robert Frost's poems “Stopping by Woods on a Snowy Evening.” He liked it that he recorded it on his home answering machine, which would lead to one of the most unusual1of his life.

    When Phil returned from his vacation, he listened to his voice 2  One gentleman caller 3for dialing the wrong number. But, he added, he'd really 4the poem. Phil laughed and thought nothing more of it— 5the phone rang a few days later.

    Phil 6John's hollow voice immediately, who said sorry to7, but he was calling to hear the8again. The two men talked. It turned out that his brother's phone number was9from Phil's by one digit(数字), thus the wrong number. Before hanging up, Phil told John to 10anytime, whether to hear the poem or just to have a chat.

    That was 11 years ago. They've spoken on the phone a few times a month ever since. It is John who is 11the starter of most calls. However, Phil will ring if a long while has passed. Not 12  John has been in poor health. His special voice is just the 13of some heart trouble. They seem to always 14when there's been a big sports event. The man like to discuss 15most. John will also 16Phil on his life. Slowly, their conversations have grown much more 17  When asked what drew them together, Phil18that they were old friends. They planned to meet twice, but circumstances went19them. Their friendship is based on the simple act of picking up the phone. “My best friend is someone I've not yet met 20 ” says John. It's as simple as that.