一定强度的声波作用于人耳引起的一种识别声音强弱的感觉,称为()。 A.声强级 B.声

题型:单项选择题

问题:

一定强度的声波作用于人耳引起的一种识别声音强弱的感觉,称为()。

A.声强级

B.声强

C.听阈

D.响度

E.声压级

考点:北京住院医师耳鼻咽喉科Ⅰ阶段耳科学耳科学题库
题型:单项选择题

某公司有一台设备,购于两年前,现在考虑是否需要更新。该公司所得税率为25%,要求的最低投资报酬率为10%,如果更新,每年可以增加销售收入100万元,有关资料见下表(单位:万元)。

项目 旧设备 新设备
原价 520 630
税法规定残值 20 30
税法规定使用年限(年) 5 5
已用年限 2
尚可使用年限 4 4
每年操作成本 200 150
两年末大修成本 40
最终报废残值 5 10
目前变现价值 207.2
按照税法规定,旧设备采用双倍余额递减法计提折旧,新设备按照年数总和法计提折旧。预计未来的四年每年都需要交纳所得税。
要求:
1.按照税法规定计算旧设备和新设备每年的折旧额;

题型:单项选择题

阅读理解。

     Early people had very little effect on the environment. They lived in eaves in very small ' clan' groups.

They collected or killed only enough for the clan's survival. Early clans were nomadic, which means that

they did not stay in one place. Instead, they moved around, following the animals that were their main

food source and seeking areas where seasonal plants grew wild. Moving around seasonally helped to

protect the environment. The land had time to recover and animals had time to breed (繁殖) before the clan

returned for the next season.

     As time went by, these small family clans joined with others to form larger groups for protection. Joining

with other clans gave them more hunters and more women to help cut up the meat and share it between

families. Eventually, people tamed (驯养) wild animals such as dogs and horses. People settled around rivers

and fertile plains to share responsibilities and duties. Then, people began to plant crops instead of moving to

areas where the plants grew. This development changed the environment.

     Traditional forms of work also changed. Some people were hatter at performing a particular task than

other clan members, so they began to specialize in things they were good at doing. This also meant that they

began to exchange their goods for things that others produced.

     People began to communicate with distant tribes. Land was cleared for roads. Foreign plants and animals

were transported to places where they had not existed before. Specialization also gave people more free time.

So art, dance and music became important ways of expressing feelings and thoughts. This was how many

great civilizations started.

     Compared to the past, modern civilization has experienced many changes to become the highly developed

society that exists today. Populations have increased rapidly. Forests have been cleared for farms. Inventions

and technology have made work easier.

     However, pollution and other serious problems have also resulted from human progress. As concerned

citizens, it is up to us to learn from past mistakes and to help maintain and improve our environment.

1. Early tribes didn't have much effect on animal population because _____.

A. they kept animals for themselves

B. they ate only vegetables

C. they killed only enough for food

D. they loved animals

2. The main purpose for small clans to join together was _____.

A. to hunt animals

B. to seek safety

C. to share caves

D. to protect environment

3. Which of the following is TRUE according to this passage?

A. Early people moved to new places looking for new sources of food.

B. Modem civilization began when people started to live together in big groups.

C. Modem advancements are always good for the environment.

D. People began to exchange goods because they didn't have enough money.

4. It can be concluded from the passage that _____.

A. human progress has brought civilization to the society

B. civilization has improved traditional forms of work

C. our environment has been affected by human progress

D. early people understood environmental protection

题型:单项选择题

由于雨过天晴揭膜不及时,棚内温度过高造成的幼苗叶片或生长点灼伤的现象称为()。

A.烟害

B.冻害

C.热害

D.高温障碍

题型:单项选择题

锚杆长度一般为其间距的()倍

A、1~2

B、3~4

C、2~2.5

D、5~6

题型:单项选择题

热电偶测量端的焊接方法有哪些?工艺上有什么要求?

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