A．pileB．heatC．powerD．pressure

A．useB．heatC．pressureD．form

A．forceB．volumeC．powerD．control

Ammeter is to measure the _____.A.currentB.voltageC.powerD.frequency

All secrets may eventually come to______.A．lightB．tunnelC．powerD．terms

【C2】A．attentionB．resultC．powerD．trend

【C9】A．abilityB．effectC．powerD．accuracy