在冷凝器接近标准圆锥接头处打四个穴孔.Make four indentations into the condenser near the standard cone joint.上述装置也称为圆锥摆.The present device is also called a conical pendulum.设有一组平行线与圆锥曲线相交.Consider a family of parallel lines that cut the co...
我们多年来都开着一辆生锈的旧货车四处旅行。We spent years travelling around in a rusty old van.闪电在货车周围炸开时，情景异常壮观。It was unbelievably dramatic as lightning crackled all round the van.马撞在货车上发出砰的一声巨响。There was a loud thump as the horse crashed i...