某干洗剂的主要成分是四氯乙烯(化学式为 C2Cl4),它是一种易挥发、可能致癌的

题型:填空题

问题:

某干洗剂的主要成分是四氯乙烯(化学式为 C2Cl4),它是一种易挥发、可能致癌的有毒物质。请根据信息回答下列问题:  

(1)刚刚干洗后的衣服,往往需要挂在通风处晾二段时间。请你用微粒的观点解释这样做的原因_______________________________。  

(2)四氯乙烯的化学性质是________________________。

(3)有些干洗店用装有活性炭的新款干洗机取代旧款干洗机,这一变化可将服装上残留的有毒物质含量大大降低,新款干洗机的这一改进是利用了活性炭的______________性。

考点:活性炭和木炭的结构和用途分子的特点物理性质和化学性质的区别和应用
题型:填空题
看看,选选。
( ) 1. __ye
( ) 2. b__dy
( ) 3. __ar
( ) 4. f__ce
a. a
a. o
a. o
a. u        
b. e
b. a
b. e
b. a
题型:填空题

Would you be surprised to learn that your eyes are like an eagle’s eyes in some ways? You and an eagle can see colors. And an eagle’s eyes and yours are about the same size. But therre are a lot more of a special type of cell in an eagle’s eyes than in your eyes. These cells send information to the eagle’s brain. Getting a lot of information helps an eagle see much better than you. In fact, eagle can spot a fish in the sea from a mile away.

You and an eagle have eyes that make tears. Your eyes make watery tears that clean your eyes. An eagle’s eyes for watery tears and oily tears. Eagles dive into the sea to catch fish. The oily tears guard their eyes from the saltwater.

Like you, eagles have eyelids. You have two eyelids, and you close your eyes by lowering the top lid. When eagles close their eyes, their bottom lids raise up. Eagles have a third eyelid that moves across the eye every few seconds. It wipes dust away from the eye. An eagle can see through this third eyelid. The eyelid guards the bird’s eyes when it swoops at 100 miles an hour after its prey(捕食).

小题1:How are your eyes like an eagle’s eyes?

A. You both have three eyelids.       B. You bothe see colors.

C. Your eyes have the same number of special cells as an eagle’s eyes.

小题2:Your eyes help you learn about the world. An eagle’s eyes help it_______.

A.catch its prey

B.fly fast

C.blink its eyelids

D.send information小题3:Unlike your eyes, an eagle’s eyes __________.

A.have cells

B.can see colors

C.have an extra eyelid

D.form tears小题4:How is the way an eagle blinks(眨眼) different from the way you blink?

A.An eagle moves both its top and bottom eyelids.

B.An eagle moves its bottom eyelid.

C.An eagle moves its top eyelid.

D.An eagle uses three eyelids to blink.小题5:The word “swoop” is closed in meaning to _________.

A.俯冲

B.飞翔

C.展翅

D.冒险

题型:填空题
The teacher said _____ wanted to go to the cinema must be there before 6:00.

A. those who
B. that
C. who
D. which
题型:填空题

关于属性抽样与变量抽样的论述中,正确的是( )。

A.属性抽样可了解非会计信息,而变量抽样用来了解会计信息

B.属性抽样往往用于控制测试,而变量抽样往往用于实质性测试

C.属性抽样要依据非统计抽样,而变量抽样的依据是统计抽样

D.属性抽样误差单位为百分比,而变量抽样的误差单位为金额

题型:填空题

患者,女,24岁,已婚。月经周期3/28天,此次月经逾期9天, * * 少量流血,小腹隐痛,尿妊娠试验(+),既往曾2次流产。其诊断是()

A.妊娠腹痛

B.胎动不安

C.胎漏

D.堕胎

E.滑胎

更多题库