It is required that we _____at six.A.will arrive B.arrived C.arrive D.would arrive请问C项中should省略为什么不行

英语翻译It is required that the instrument should be tested before it is actually used. it is required that..和it is requested .that...有什么区别如:有人要求名人应该纳税用哪个 _____ in the regulations that you should not tell other people the password.A.What is required B.What requires C.It is required D.It requires It is required that every student___work___hard.为什么不用works,不是every每一个么. It is required that each room▁▁（clean）thoroughly. It is required that the project should be finished at once _____in the regulation that you should not tell other people the password of your email account,A.What is required C,It is required We know a goal is only as worth as the effort that's required to achieve it. It is required that whoever enters show his pass so as to be allowed to get in,__? It is required that the plan__out firmlyAbe carried out Bmust be carried Cwill be carried D.carriesWhy? It is required that the committee()the plan before the coming Cristmas.为什么用present不用will present ------------in the regulations that you should not tell other people the password of your bank account.A.What is required B.What requires C.It is required D.It requires _____ in the regulations that you should not tell other people the password of your email account.A.what is required B.what requires C.It is required D.It requires 英语翻译in the rugulations that you should not tell other paople the password of your mail accountA.what is required B.what a requires C.it is required D.It requires是在 in the regulations 的前面 some people think that all ( ) to make a good player is courage.A are required B is required C require D that is required It is required that all woule-be employees___ citizens of this country.A.beB.areC.is D.will be怎么选? It is required that the students ___ their homework on time .A .would hand in B .should hand in C .hands in D .is to hand in It is required that the machine be oiled as frequently as necessary为什么用Be oiled而不用Must be oiled ,is oiled或者Will oil求详解