问题
选择题
把干净的玻璃板吊在弹簧测力计的下面,记下测力计的读数.如图所示让玻璃板的下表面接触水面,然后稍稍用力向上拉,发现弹簧测力计读数变大.其原因是玻璃板与水的接触面之间存在( )
A.摩擦阻力
B.大气压力
C.分子引力
D.分子斥力
答案
答案:C
把干净的玻璃板吊在弹簧测力计的下面,记下测力计的读数.如图所示让玻璃板的下表面接触水面,然后稍稍用力向上拉,发现弹簧测力计读数变大.其原因是玻璃板与水的接触面之间存在( )
A.摩擦阻力
B.大气压力
C.分子引力
D.分子斥力
答案:C
选词填空,并注意词形变化。 | |
2. The windows came from old buildings that were being _____. 3. The roof is _____ discarded tiles. 4. She recently _____ from the Help Save Our Planet Society. 5. She sold them to _____ for the Children's Hospital. |