如图,我国“歼15”舰载机已在“辽宁舰”上成功起降,“辽宁舰”成为真正意义上的航

题型:填空题

问题:

如图,我国“歼15”舰载机已在“辽宁舰”上成功起降,“辽宁舰”成为真正意义上的航母。舰载机往航母甲板上降落时,以_______为参照物,舰载机是运动的;舰载机着舰后由于_________继续高速运动,所以必须适时放下着舰钩,钩住甲板上的拦阻索,达到强行减速目的,其中涉及的力学知识是_______(选填一项);当舰载机停在航母水平甲板上时,其重力与_______力属于平衡力。

考点:牛顿第一定律
题型:填空题

根据短文内容在下面的每个句子的空格中填上一个词,使其意思与原文相符。

         This is a story about a monkey. An old man had a monkey. The old man liked the monkey very much.

The monkey was very clever. When birds came to the garden, he drove them away. He also helped the old man

in many other ways.

          One hot afternoon in the summer, the old man was sleeping in his chair in the garden. A fly (苍蝇) came

and sat on the old man's nose. The monkey drove it away. Soon the fly came back and sat on the old man's nose

again. Again the monkey drove it away. Again and again, the monkey became very angry. He jumped up and ran

to pick a large stone. When the fly was on the old man's nose again, the monkey hit it hard with that stone. The

fly fell off, but the old man's nose was broken.

          Well, many people, sometimes do things just like monkey. They do things too hastily (草率地) but they

don't think much before they do. Maybe they sometimes bring us trouble, though they mean to do something

good.

1. The monkey could do a ________ of __________ for the old man.

2. When the old man was __________, a fly _________ and sat on his nose.

3. The monkey got very angry because he _________ drive the fly ___________.

4. At last the fly was ___________ but the old man's nose was ____________.

5. We can learn from this story that we must think ___________ ___________ we do anything.

题型:填空题

低热量食物是指含淀粉、糖类等碳水化合物类较少的食物,通过食用低热量食品,可以有效控制能量的摄入量,避免多余能量在体内以脂肪形式储存下来,如果体重已经较重的人改为食用低热量食品,则可在保持饱腹感的同时达到减肥效果。另外,有许多人认为,低热量食物对糖尿病患者也十分有益。以下哪项为真,最能支持上述推论?

A.改食用低热量食物需要逐步进行,否则会引起机体代谢紊乱 

B.低热量食品可以降低超重或糖尿病患者的体重,但需要补充其他营养 

C.低热量食品可适当增加进食量,满足饱腹感,享受吃饱的乐趣 

D.研究表明低热量饮食可减少脂肪在胰脏中的沉积,恢复胰岛素的分泌

题型:填空题

当线圈中电流改变时,线圈中会产生自感电动势,自感电动势方向与原电流方向[ ]

A.总是相反

B.总是相同

C.电流增大时,两者方向相反

D.电流减小时,两者方向相反

题型:填空题

短周期元素X、Y、Z的原子序数依次递增,其原子的最外层电子数之和为13。X与Y、Z位于相邻周期,Z原子最外层电子数是X原子内层电子数的3倍或者是Y原子最外层电子数的3倍。下列说法正确的是[ ]

A.X的氢化物溶于水显酸性

B.Y的氧化物是离子化合物

C.Z的氢化物的水溶液在空气中存放不易变质

D.X和Z的最高价氧化物对应的水化物都是弱酸

题型:填空题

下列关于码的叙述中,正确的是

A.在一个关系中,不可能存在两个不同的元组在码属性上取值相同

B.属性是一个元组区别于其他元组的依据

C.在一个关系中,可能存在码或码的一部分为空值的元组

D.码不是一个元组赖以存在的条件

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