He became convinced of the need for cheap editions of good quality writing...他开始相信大众对优秀作品的普及本有需求。He became convinced of the need for cheap editions of good quality writing.他开始相信大众对优秀作品的普及本有需求。In the course of collating g...
我们多收集一些这类的文章吧。Let's have some more articles of this sort.宝石类的关税率很高.There is a very high tariff on jewelry.海洋里有许多诸如鲸鱼和海豹类的海生哺乳动物.There are lots of marine mammals such as whales and seals in the sea....
中心力是由球对称的势能函数而来的力.A central force is one derived from a potential - energy function that is spherically symmetric.有心力是一种径向力,它的大小只取于离原点的距离.A central force is a radial force which depends only on the distance from the orig...