Pentacontane
五十烷
🗣️ 情景例句
The newspapers don't come out till about ten o'clock.
报纸要差不多十点钟才出来。
No,that's not my book.
不，那不是我的书。
Yet a great many processes depending on such research are sought for with complete secrecy until the stage at which patents can be taken out.
然而，依赖这种研究的很多工艺程序是在完全保密的情况下进行的，直到可以取得专利权的阶段为止。