Pitchblende and chalcolite are much more radioactive than uranium itself.沥清铀矿和铜铀云母比纯铀的放射性强得多.Chalcolite ( crystallized phosphate of copper and uranium ) is about twice as radioactive as uranium.铜铀云母 ( 铜和铀的磷酸盐结晶体 ) 的放射性是铀...
长凳的靠背可以向前翻折成一张桌子。The back of the bench folds forward to make a table.我们坐在公园的长凳上,看儿童嬉戏.We sat down on the park bench and watched the children play.白杨树下有一条长凳.There's a bench under a poplar tree....
他刹住了舵把,系紧帆脚索,伸手到船梢下去拿棍子.He jammed the tiller , made the sheet fast and reached under the stern for the club.老人系紧帆脚索,卡住了舵柄.The old man made the sheet and jammed the tiller.窝里挟着舵柄,一只脚踩住了帆脚索,就这样办了.So he did the tiller under...