问题 单项选择题

用贯入阻力仪测定不同水泥品种,不同外加剂、不同砼配合比以及不同气温环境下砼拌合物的凝结时间,绘制贯入阻力一时间曲线图,从曲线图求得的()为砼的初凝和终凝时间。

A.2.5MPa和25MPa

B.3.5MPa和25MPa

C.3.5MPa和28MPa

D.3.5MPa和30MPa

答案

参考答案:C

完形填空
完形填空。
     There are four kinds of satellites. The first kind of satellite studies the  1  of the earth. They are used to  2  
maps. They also help countries to see where they may  3  oil or gold.
     The second kind guides ships and planes. A ship or plane can send  4  to the satellite, and the satellite can
find out where it is.
     The third kind studies  5 . These satellites  6  clouds and strong winds moving across the earth. They
warn countries when very  7  weather is coming. They take photos of the earth from thousands of kilometers
above it and  8  the photos to a weather station on the ground.
     The fourth kind is used for communication. Telephone calls  9  countries can be sent by these satellites.
Some can carry hundreds of calls at one time. The calls are sent to the satellite,then the satellite sends them
to a station in the country Which is being phoned. These satellites  10  carry television pictures. They can
receive and send about eight programs at a time. How amazing!
( )1.A. chemistry
( )2.A. make    
( )3.A. buy      
( )4.A. a letter  
( )5.A. the air   
( )6.A. see      
( )7.A. bad      
( )8.A. send     
( )9.A. in       
( )10.A. too     
B. geography 
B. buy      
B. need      
B. telephone  
B. the weather
B. watch     
B. fine      
B. carry     
B. of       
B. either     
C. physics   
C. carry   
C. find    
C. money    
C. the rain  
C. search   
C. nice    
C. take      
C. between   
C. also    
D. biology   
D. sell      
D. use       
D. a message 
D. the cloud 
D. look      
D. warm                                           
D. bring     
D. among     
D. neither   
选择题