铜是热和电的良导体.Copper is a good medium for the conduction of heat and electricity.木头是热和电的不良导体.Wood is a poor conductor of heat and electricity.铜是电的良导体.Copper conducts electricity well....
He struggled to hold the bike down on the banked corners.拐过斜弯时他竭力将自行车把稳。George struggled wildly, going under and resurfacing at regular intervals.乔治疯狂地挣扎，不断在水面上浮浮沉沉。I struggled into a bathrobe and staggered down the stai...