He sagged wearily back in his chair.他疲倦地瘫坐到椅子上。Morrison took the news badly and from then on his spirits noticeably sagged.这消息对莫里森打击很大，从那以后，他明显萎靡不振。His upper lip was flat, but the lower one sagged.他上唇扁平，下唇耷拉。There were p...
物理学研究力学、热学 、 光学 、 声学和电学.Physics studies mechanics , heat, light, sound and electricity.这两个学生都做了不少电学实验.Both students have made quite a few experiments on electricity.从量子电动力学可以得出所有已知的电学 、 力学和化学定律.Out of quantum electrodyna...
He died in unexplained circumstances.他死因不明。Soon after leaving Margate, for some unexplained reason, the train was brought to a standstill.离开马盖特不久，不知什么原因，火车突然停了下来。Soon after leaving Margate, for some unexplained reason, t...
一道拦河坝将会在上游拦住水流，抬升水位。A barrage would halt the flow upstream and lift the water level.拦河坝把河流控制住了.Rivers are controlled by dams.我们决定筑一道拦河坝.We decided to dam the river....