A:蟾蜍、鳄鱼
B:青蛙、水蚤
C:娃娃鱼、蟾蜍、青蛙
D:河马、中华鲟
一电压表的量程标定不准确,某同学利用如图甲所示电路来测量该电压表的实验量程Um,所用器材有:
A.量程不准的电压表V1,内阻r1=10kΩ,量程标称为5V;
B.标准电压表V2,内阻r=6kΩ,量程3V;
C.标准电阻R1,电阻4kΩ;
D.滑动变阻器R2,总电阻20Ω;
E.电源E,电动势9V,内阻不计;
F.开关S,导线若干.
回答下列问题:
词语运用
①The old man is d____.He can't hear anything.
②My dog is m____.Can you help me find it?
③All of them are ____(注视) at the computer screen.
④We don't know whether he's ____(活着)or dead.
⑤The road was so narrow(狭窄)that cars were unable to ____(通过).
读我国东部季风区某地等高线地形图,回答:
如图的等高线地形图所对应的地形景观素描图是( )