we witnessed a man-made satellite ____________(launch) into the outer space填什么,具体分析下

we witnessed a man-made satellite ____________(launch) into the outer space填什么,具体分析下 The last half of the nineteenth century __the steady improvement in the means of travel.A .has witnessed B.was witnessed C.witnessed D.is witnessed we call a sick man a p When we see a very sick man .we should call ( ) ). 英语翻译第一句是Around the end of the first century AD,a Roman writer called pliny wrote about a terrible volcanic eruption that he had witnessed as a young man.速度………… 请问这句话怎么翻译好?尤其是“we have witnessed.”该怎么翻译?In the past few years we have witnessed intensive research activity in the development of a variety of electronic devices based on the wide band gap refractory semicondu 英语翻译英语翻译：在过去二十年里,我们见证了巨大的经济和社会的进步.这儿用we had witnessed还是用we have witnessed? witness 的用法：The great wall _____ the history of war.A,witnesses B.witnessed C.has witnessed The last half of the nineteenth century __the steady improvement in the means of travel.A .has witnessed B.was witnessed C.witnessed D.is witnessed 这题选什么呀! Never before can we witness such a preposterous state of affairs as we are seeing today.can we witness 处改错a could we have witnessedb have we witnessed c should we witnessd could we witness答案d,我选的b,why详细的解释,谢谢了 I'm a special man啥意思? I'm a man teacher.复数形式 I'm a thinking man 是什么意思? I'm a thinking man 意思 As we were leaving,a man called from a car. How many roads must a man walk down,before we called him a man As we all known,the economy has witnessed rapid development in the past 30 years 语法错误On the other hand,a laptop is so portable that draws people 's attention.有什么语法错误 we have no dealing with a selfish man中文意思