已知锌的逸出功为3.34eV,用某单色紫外线照射锌板时,逸出光电子的最大速度为1

题型:计算题

问题:

已知锌的逸出功为3.34eV,用某单色紫外线照射锌板时,逸出光电子的最大速度为106m/s,求该紫外线在水中传播时的波长λ(电子质量me=9.11×10-31kg,普朗克常量h=6.63×10-34J•s,1eV=1.60×10-19J, 水的折射率n = 1.33)

考点:光电效应方程
题型:计算题

关于淀粉,下列说法正确的是()

A.淀粉的基本构成单元是果糖

B.淀粉的最终水解产物是葡萄糖

C.淀粉有直链淀粉、支链淀粉和抗性淀粉三种

D.所有的淀粉均能够被消化吸收

E.淀粉含量高的食物血糖指数较低

题型:计算题

患者,男性,62岁。冠心病伴房颤,室率90次/分,血压130/80 mmHg,静息时无心绞痛发作,中等活动后稍感胸闷,心前区不适,无心衰史,冠脉造影示右冠状动脉主干狭窄70%,左前降支狭窄80%,超声心动图示EF55%,FS25%,左室前壁运动减弱。ECG示SFT改变。拟腹腔镜下行胆囊切除术,该患者术前用药不宜使用()

A.阿托品

B.长托宁

C.咪达唑仑

D.吗啡

E.地西泮

题型:计算题

阅读理解。

     It is often necessary to release a fish, that is, set it free after catching, because it is too small, or you just

don't want to take it home to eat. In some cases, releasing fish is a good measure that will help keep fish

variety and build their population size. The Department of Game and Inland Fisheries (DGIF) encourages

fishermen who practice catch-and-release fishing to use a few simple skills when doing so. The advice

provided below will help make sure that the fish you release will survive (存活) to bite again another day. 

     -When catching a fish, play it quickly and keep the fish in the water as much as possible. 

     -Don't' use a net in landing the fish and release it quickly to prevent it from dying.

     -Hold the fish gently. Do not put your fingers in its eyes. Don't wipe the scales (鱼鳞) off the fish

because it might cause it to develop a disease and reduce its chance of survival.

     -Remove your hook (鱼钩) quickly. If the hook is too deep or hooked in the stomach, cut the line and

leave the hook in. The hook left inside will cause no serious problem to the fish.

     -Take good care of the fish by moving it gently in water. Release the fish when it begins to struggle and

is able to swim.

     -Do not hold fish in a bucket or some other containers and later decide to release it. If you are going to

release a fish, do so right away. With a little care and by following the suggestions given above, you can

give the released fish a better chance of survival.

1. People sometimes set a fish free after catching it because they ______

A. don't want it to die

B. hope it will grow quickly

C. don't want to have it as food

D. want to practice their fishing skills

2. Which of the following will probably make a fish ill?

A. Taking the hook off it.

B. Removing its scales.

C. Touching its eves.

D. Holding it in your hand.

3. A proper way to release a fish is to ______.

A. move it in water till it can swim

B. take the hook out of its stomach

C. keep it in a bucket for some time

D. let it struggle a little in your hand

4. What is the purpose of the test?

A. To show how to enjoy fishing.

B. To persuade people to fish less often.

C. To encourage people to set fish free.

D. To give advice on how to release fish.

题型:计算题

果农冯某承包有100亩苹果园,2000年秋季获得了大丰收,但冯某不懂得销售的途径和方法,在农村的集市上销售量又很小,遂委托市里的远房亲戚陈某在市里代为销售,并处理相关事宜,双方约定:苹果量高每斤0.8元,陈某按销售总额的15%提成,于每次陈某交还货款时结算;陈某根据市里苹果需求量的大小及时通知冯某,以便冯某准确向陈某送货。合同签订后,陈某即积极活动,先后以自己的名义与王母阁市场和解放路市场签订了每天供应500公斤苹果的合同,每斤价格为0.85元;并与汤某等商贩口头约定可到自己家里随时提货,价格面议。

请回答以下问题:

对于陈某签订合同和每天向市场送货所花的费用,如果双方没有约定,那么()。

A.冯某无须预付

B.陈某可以垫付

C.陈某可以要求冯某预付

D.陈某垫付的费用,冯某应当偿还并支付利息

题型:计算题

尿毒症最早期出现的表现为

A.贫血

B.高血压

C.胃肠道症状

D.心力衰竭

E.出血

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