如图所示,在锥形瓶内放一装有氯化钠饱和溶液的试管及浓硫酸,塞紧橡皮塞后,放在托盘

题型:选择题

问题:

如图所示,在锥形瓶内放一装有氯化钠饱和溶液的试管及浓硫酸,塞紧橡皮塞后,放在托盘天平上称重.放置一段时间后,试管中有晶体析出,天平仍平衡(不考虑温度变化).下列说法不正确的是(  )

A.该变化符合质量守衡定律

B.试管中氯化钠溶液溶质质量分数不变

C.浓硫酸具有吸水性

D.锥形瓶中浓硫酸溶质质量分数变小

考点:关于溶液的计算浓硫酸的稀释质量守恒定律固体溶解度
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异位妊娠常见的着床部位是()。

A.卵巢

B.腹腔

C.输卵管

D.子宫角

E.子宫颈

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检验的()是指交检批所接受抽样检验的宽严程度。

题型:选择题

A hobby can be almost anything a person likes to do in his spare time. Hobbyists raise pets, build model ships, weave baskets, watch birds, hunt animals, climb mountains, raise flowers, fish, ski, skate, and swim. Hobbyists also paint pictures, attend concerts and plays, and perform on musical instruments. They collect everything from books to butterflies, and from shells to stamps.

People take up hobbies because these activities offer enjoyment, friendship, knowledge, and relaxation. Sometimes they even produce financial profit(利润). Hobbies help people balance between work and play. Hobbies also offer interesting activities for persons who have retired. Anyone, rich or poor, old or young, sick or well, can follow a satisfying hobby, regardless of (不论)his age, position, or income.

Hobbies can help a person’s mental and physical health. Doctors have found that hobbies are valuable in helping patients recover from physical or mental illness. Hobbies give bedridden or wheel-chair patients something to do, and provide interests that keep them from thinking about themselves. Many hospitals treat patients by having them take up interesting hobbies or pastimes.

In early times, most people were too engaged in making a living to have many hobbies. But some persons who had leisure(休闲)did enjoy hobbies. The ancient Egyptians played games with balls made of wood or pottery.

People today have more time than ever before for hobbies. Machines have reduced the amount of time they must spent on their jobs. Hobbies provide variety for workers who do the same monotonous(单调的) tasks all day long. More people are retiring than ever before, and at an earlier age. Those who have developed hobbies never need to worry about what to do with their newly found leisure hours.

Sir William Osier, a famous Canadian doctor, expressed the value of hobbies by saying, “No man is really happy or safe without a hobby.”

小题1:It seems that people who     may spend more time enjoying their hobbies.

A.have little money

B.have much money

C.have retired from their work

D.have left school小题2:The underlined phrase “recover from” in the third paragraph means     .

A.get back

B.become healthy again

C.become calm

D.supply with a new cover小题3:In early times, most people spent less time on their hobbies, because     .

A.they were busy in making a living

B.they suffered from illnesses.

C.they were brave and hard-working

D.they were not interested in them.小题4:What’s the writer’s opinion about hobbies?

A.People all over the world have the same hobby.

B.Machines also have their hobbies.

C.Hobbies are popular among people in Egypt.

D.People should have hobbies in their spare time.

题型:选择题

生锑 ( )

A.18

B.21

C.16

D.20

题型:选择题

当机房设有过桥走线架(槽道)且机房净高为3200-3300mm时,确定列架高度时不应大于()。

A.3050mm

B.3200mm

C.3300mm

D.2400mm

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