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
搜题请搜索小程序“爱下问搜题”
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
参考答案：C
| 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! | ||||
|