他们不时地听到大卡车的轰鸣声。Now and then they heard the roar of a heavy truck.人群里不时发出几声抱怨和欢呼。Scattered groans and whoops broke out in the crowd.要抬起头，不时看看四周。Keep your head up, and look around you from time to time....
One kind contains the liver moss grain shape, arborization inclusions of agate.一类包含苔粒形, 树枝状玛瑙包裹.The way to influence the concrete strength is floc and arborization formed in concrete.影响混凝土强度的方式是在混凝土中形成絮状集合体和树枝状细脉....
We were chaperoned by our aunt.我们由婶子陪着。I managed to hold her once at a dance - chaperoned, of course.在一次舞会上, 当然是有成年人在场,我设法同她跳了一曲舞.The Chinese tourists were also prohibited from leaving their chaperoned groups.中国游客亦不得离开受监...