所有的性激素, 例如雌激素 、 黄体酮和睾酮都是类固酮.All the sex hoymones, e . g. estrogens, progesterone, and testosterone, are steroids.所有的性激素, 例如雌激素, 黄体酮和睾酮都是类固醇.All the sex hormones, e . g . estrogens, progesterone, and testosterone, are ste...
窗户通常是封闭的。Windows are usually sealed off.他们接触的事不多，从这一方面来说这是个封闭的社团。It is a closed society in the sense that they've not been exposed to many things.宇宙究竟是开放的,还是封闭的?Is the universe open or closed?...
Isoamyl butyrate was synthesized by using ceric sulfate as the catalyst.以硫酸高铈为催化剂,正丁酸和异戊醇为原料合成了正丁酸异戊酯.In the presence of ethanonitrile and glycol, anisole reacts with ammonium ceric nitrate to form o - nitroanisole.在乙腈、聚...
The leading player is ill. Let his understudy to appear on the scene.主角演员病了, 让他的替角出场.The understudy was substituted when the leading actor fell ill.主角演员患病,由替角代替演出.The understudy is substituted when the leading actor fall...
The field were so close that they would have caught us if I hadn't begun the sprint.其他参赛选手紧随身后，如果不是我开始冲刺，他们就会赶上我们了。She'd been caught from behind and hadn't a prayer of freeing herself.有人从后面抓住她，她不可能脱身。We ha...