燃灯法的灯和灯芯总要用()的化学纯石油醚洗剂、干燥.
A.100℃左右
B.50~60℃
C.60~90℃
D.120~150℃
参考答案:C
---Where’s the little elephant?
---It’s said it ___ in the hospital.
A.was examined
B.will be examined
C.is being examined
D.has been examined
根据R=UI,下列说法正确的是( )
A.加在导体两端的电压越大,导体的电阻越大
B.导体中的电流强度越大,导体的电阻越小
C.导体的电阻跟电压成正比,跟电流强度成反比
D.导体的电阻与导体两侧的电压无关