某种甜味剂A的甜度是蔗糖的200倍,由于它热值低、口感好、副作用小,已在90多个

题型:填空题

问题:

某种甜味剂A的甜度是蔗糖的200倍,由于它热值低、口感好、副作用小,已在90多个国家广泛使用。A的结构简式为

已知:

①在一定条件下,羧酸酯或羧酸与含-NH2的化合物反应可以生成酰胺,如

②酯比酰胺容易水解。

请填写下列空白:

(1)在稀酸条件下加热,化合物A首先生成的水解产物是:________和________。

(2)在较浓酸和长时间加热条件下,化合物A可以水解生成:________、________和________。

(3)化合物A分子内的官能团之间也可以发生反应,再生成一个酰胺键,产物是甲醇和___________。(填写结构简式,该分子中除苯环以外,还含有一个6原子组成的环)

考点:
题型:填空题

婴儿对看得见而又拿不到的玩具,产生不愉快情绪,但当玩具在眼前消失时,不愉快情绪也很快消失,这是()。

A.情绪的内隐性

B.情绪的依赖性

C.情绪的受感染性

D.情绪的情境性

题型:填空题

同桌的体重是[ ]

A.4吨    

B.35千克    

C.800克

题型:填空题

Here in the hills were buffaloes (野牛). I had even, in my very young days — when I could not live till I had killed one of each kind of African animal — shot a bull out there. Later on, when I was not so interested to shoot as to watch the wild animals, I had been out to see them again. But twice I had to go back without success.

But one afternoon as I was having tea with some friends outside the house, Denys came flying from Nairobi and went over our heads westwards; a little while after he turned and came back and landed on the farm. I drove down to the plane to bring him back, but he would not get out of his plane.

“The buffaloes are out feeding in the hills,” he said, “come out and have a look at them.”

“I cannot come,” I said. “I have got a tea-party up at the house.”

“But we will go and see them and be back in a quarter of an hour,” he said.

This sounded to me like the suggestions which people make to you in a dream. So I went up with him. It did not take us long to see the buffaloes from the air; we counted them as they peacefully mixed and separated on the open ground closed in by bushes. There was one very old big black bull, and a number of young ones; if a stranger had come near to them they would have heard or smelt him at once, but they were not prepared for something from the air. They heard the noise of our machine and stopped feeding, but they did not seem to be able to look up. In the end they realized that something very strange was about; the old bull first walked out in front of the others. Suddenly he began to go down the valley side and after a moment he broke into a run. The whole group now followed him, rushing hurriedly down into the buses. In a small wood of low trees they stopped and kept close together. Here they believed themselves to be out of sight. We flew up and away. It was like having been taken there by a secret unknown route.

When I came back to my tea-party the teapot on the stone was still so hot that I burned my fingers on it.

小题1:The writer drove to the plane ________.

A.to pick Denys up and take him back to the tea-party

B.to have a talk with Denys

C.to do some repairs for Denys

D.because they wanted to go up in the plane小题2: Denys said it would only take a quarter of an hour to go and see the buffaloes ________.

A.but it took much longer than that

B.and he was right

C.if they went by a secret route

D.but it wasn’t a serious suggestion小题3:When the buffaloes heard the noise of the plane, they ________.

A.looked up at it

B.ran away immediately

C.continued feeding

D.were uncertain what to do

题型:填空题

每年平均登陆我国的台风有几次()。

A、10次

B、9次

C、7次

D、8次

题型:填空题

原料进货验收既有称大件物品的大磅秤,又要有称小件、贵重物品的台秤和天平秤,并定期()。

A.擦洗

B.校准

C.上油

D.换磅

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