问题 选择题

薄荷醇(化学式为C10H20O)可用于糖果、饮料的加香。下列有关薄荷醇的说法正确的是

A.薄荷醇属于有机化合物

B.薄荷醇由10个碳原子、20个氢原子和1个氧原子构成

C.薄荷醇中碳元素、氢元素和氧元素的质量比为10:20:1

D.薄荷醇中碳元素的质量分数约为76.9%

答案

AD

薄荷糖中只含一种物质,属于纯净物;又由于薄荷糖中含有碳、氢、氧三种不同元素,因此薄荷糖属于纯净物中的化合物.所以A选项错误.

B中未指明在1个薄荷糖分子中,因此B选项错误.

薄荷糖中碳、氢、氧三种元素的质量比为12×10:1×20:16=30:5:4,不是10:20:1,因此C选项错误.

薄荷糖中碳元素的质量分数为

12×10
12×10+1×20+16
×100%≈76.9%,因此D正确.

故选AD.

完形填空
完形填空。
Dear Sandy,
     My family and I __1__ in Nanjing, China. We are very happy. I am ___2__ student in No. 11 Middle School. Is
our school ___3___? No, it isn't very big, but it's very beautiful. There __4___ any swimming pools(游泳池) in it.
But our school ___5__ two basketball courts. There is a garden and many tall trees in our school. There are about
fifty __6__ in our school. I am in Class 2, Grade 1. My classroom is ___7___ the second floor in __8___ A. There
are twenty boys and twenty-five boys in my class. Miss Fang is our Chinese teacher. __9__ is a very good teacher.
We all like her very much.
     May(愿) you be   10  ! Hope(希望) to see you soon(尽快).
                                                                                                                                                                        Yours,
                                                                                                                                                                         Lily
(      )1. A.am      
(      )2. A.a        
(      )3. A.small    
(      )4. A. is      
(      )5. A.have    
(      )6. A.class    
(      )7. A.at      
(      )8. A.building
(      )9. A.He      
(      )10.A.thin    
B.is          
B.an          
B.big        
B.isn't      
B.has        
B.classs      
B.in          
B.Building    
B.he          
B.slim        
C.are          
C.the          
C.beautiful    
C.aren't      
C.there's    
C.classes      
C.between      
C.the building
C.She          
C.happy        
D.be          
D./          
D.pretty      
D. are        
D.there're  
D.class's    
D. on        
D.the Building
D. she        
D.sad        
阅读理解

阅读理解。

     That summer an army of crickets (蟋蟀) started a war with my father. Dad didn't care for insects much

more than Mamma, but he could tolerate a few living in the basement. Mamma was a city girl and she said

a cricket was just too noisy. Then to prove her point she wouldn't go to bed. She drank coffee and smoked

my father's cigarettes and paced between the sofa and the TV. Next morning she threatened to pack up and

leave, so Dad drove to the store and hurried back. He sprayed poison from a jug. When he was finished he

told us that was the end of it.

     For a couple of weeks we went back to find dead crickets in the laundry. He suggested that we'd all be

better off to hide as many as we could from Mamma. I fed a few dozen to the cat who I didn't like because

he scratched for no reason.

     However, soon live crickets started showing up in the kitchen and bathroom. Mamma was upset because

she thought they were the dead crickets come back, but Dad said these were certainly new ones. He fetched

his jug of poison and sprayed all over until the whole house smelled of poison, and then he sprayed the

basement again.

     A couple of weeks later, when both live and dead crickets kept turning up, Dad emptied the basement of

junk. Then he burned a lot of old newspapers and magazines which he said the crickets had turned into nests. 

     While we ate supper that evening, the wind lifted some flames onto the wood pile. The only gasoline was

in the lawn mower's (割草机) fuel tank but that was enough to create an explosion big enough to reach the

house. Once the roof caught, there wasn't much anyone could do.

     After the fire trucks left, Mamma took the others to Aunt Gail's. I helped Dad and Uncle Burt carry things

out of the house and pile them by the road. We worked into the night and we didn't talk much, while all around

the noise of crickets broke our silence.

1. What do we know about the author's mother?

A. She didn't like insects at all.

B. She liked insects more than his father.

C. She cared for insects very much.

D. She could only tolerate a few insects.

2. The author's father drove to the store to buy ____.

A. cigarettes for himself

B. more coffee for his wife

C. some poison

D. some gasoline

3. The author fed a few dozen crickets to the cat probably to ____.

A. make his mother happy

B. help clear away the crickets

C. play with the cat

D. harm the cat

4. The author's father burned the old newspapers and magazines because he thought ____.

A. they were no longer useful

B. the crickets were afraid of fires

C. they became the home of crickets

D. the dead crickets came back to life

5. We learn from the last paragraph that ____.

A. the author's family lost their battle against the crickets

B. the author's parents learned to put up with insects

C. the author's family didn't suffer much in the fire

D. the author's parents got divorced