E．lectric insulation is made of organic substances and so gradually______with age

A．deteriorates

B．increases

C．are fouled

D．becomes better

[单选题]We have made ____ clear that the goods should be packed in cartons.A . itB . themC . thisD . which

[单选题]What made Professor Broad continue his search for more information on McKay?A． A uniform. of McKay.B． A footnote about McKay.C． A book on McKay.D． A picture of McKay.

[单选题]Lily’s father scolded her and made her promise __________ again.(A) never to do that(B) never to do what(C) never doing that(D) never doing what

[名词解释] 电击（electric shock）

[名词解释] 有机氮库 organic nitrogen pool

[名词解释] 有机物反应活性（organic reactivity）

[名词解释] 电烧伤electric burn

[主观题]When you are finished with the electric iron, don’t forget_____(关掉它). (turn)

[单选题]If an electric cargo winch is being used to lift a draft of cargo and the engine room loses all power，which will occur?（）A . A pawl，forced by a spring mechanism，will engage the teeth of the bull gear and hold the loadB . An electromagnetic brake will

[单选题]An electric heater built into some smaller diesel engines is used to （）.A . raise lube oil viscosity for easier starting in cold weatherB . increase air inlet temperatureC . increase compression ratioD . increase jacket water temperature for easier s