问题
不定项选择
| 不定项选择 |
| 可用理想电压表V、理想电流表A、变阻器R以及电键K和导线等器材来测量某一电源E的电动势和内阻，如图所示。下面给出了四个电路图，图中“＋”、“－”代表电源的正负极和电表的正负接线柱，正确的电路图是（ ） |
A． |
B． |
C． |
D． |
答案
答案：B
搜题请搜索小程序“爱下问搜题”
| 不定项选择 |
| 可用理想电压表V、理想电流表A、变阻器R以及电键K和导线等器材来测量某一电源E的电动势和内阻，如图所示。下面给出了四个电路图，图中“＋”、“－”代表电源的正负极和电表的正负接线柱，正确的电路图是（ ） |
A． |
| B． |
| C． |
| D． |
答案：B
| 用方框中所给词语的适当形式填空，使短文正确、通顺、连贯（没词限用一次）。 | |
biggest forests are in South America, Africa and South East Asia. There aren't any rainforests in Europe or North America. About 75% of all the types of animals 2 from rainforests. Thousands and thousands of animals live in rainforests. There are many beautiful birds, insects and reptiles (爬行动物). Many of them live in the trees, over 30 meters from the 3 . There are also thousands of different plants-and lots of them are tall trees! It is always hot in a rainforest and the ground is always wet. It is 4 very dark there. The rainforests are very important for us. We 5 them! The trees and other plants in the forest help to make the air that we breathe. They also help to control the 6 . They give us wood, rubber, fruits and many of our medicines. Unfortunately, in many places, the rainforests are in danger. For example, many 7 ago there was a large rainforest in Java. There were thousands of different plants and animals in the forest, but now there is nothing. People cut down the trees 8 they wanted to grow rice. They also wanted to grow rubber trees 9 rubber. Many animals lived in the rainforest. Some of them went to other parts of Java, but many of them disappeared-forever. The same thing 10 now in many other parts of the world. The rainforests are in danger! 1.________ 2.________ 3.________ 4.________ 5._________ 6.________ 7.________ 8.________ 9.________ 10._________ |