她撕下两格纸巾，然后纵向对折。She tore off two sections of paper towel and folded them lengthwise.他把那沓纸揉得嚓嚓响。He crunched the sheets of paper in his hands.她拿起一张纸，把它哗哗啦啦地塞到打字机中。She took up a sheet and ratcheted it into the typewriter....
氨的合成主要经过四道工序.There are four major steps in ammonia synthesis.试计算氮在尿素及硫酸氨的质量百分率.Calculate the percentage by mass of nitrogen in urea and ammonium sulphate.这种肥料经过化验表明氨的含量很高.Tests of the manure showed a high ammonia content...
他掀开铺盖跳下床.He threw back the bedclothes and jumped out of bed.如果你明天再迟到, 那就卷铺盖走吧!If you're late again tomorrow, you'll get the sack!自言自语的, 他这样一边叨唠,一边儿往起收拾铺盖.Muttering all this to himself, he gathered his bedding t...