已经····但是·······还要·······才能········造句

将来已经完成.i will have finished it.
如果想变成虚拟时,过去式用过去完成,那 现在完成该用什么时态呀?

Three fifths of the workers in our factory___(已经受过训练)in that technical and engineering school
给出的词(train)详解 -

我们已经知道[根号13+3][根号13-3]等于4,
因此根号13-3分之8分子分母同时乘以根号13+3,分母就变成了4,请仿照这种方法化简2+根号3分之1乘以根号5-根号3分之2

人们已经使用这种机器 They have already __ this kind of machine __ good __.
到底是put into对还是put to对？

英语习题回答 本人已经工作!
41.I must congratulate you ___ the excellent design of the new bridge.A.with B.of C.at D.on
42.I'm very sorry to have bothered you with so many questions on such a(n) ____.A.chance B.opportunity C.occasion D.situation
43.In no circumstances _______.A.smoking should be allowed on the campus B.should smoking be allowed on the campusC.should smoking allowed on the campus D.should smoking allow on the campus
44.The ______ at the military academy is so rigid that students can hardly bear it.A.tradition B.disappointment C.principle D.discipline
45.The test results are beyond ____; they have been repeated in labs all over the world.A.distance B.conflict C.bargain D.dispute
46.I'm not sure whether I can gain any profit from the investment,so I can't make a(n) ____ promise to help you.A.exact B.defined C.definite D.sure
47.If you want to _____ a pleasant visit,find out as much as possible about the manners and customs of your host country.A.assure B.ensure C.endure D.increase
48.This is a very difficult operation.It is essential that you ________ for emergency.A.are to be prepared B.would preparedC.be prepared D.must be prepared
49.A good way to ___ your vocabulary is to read a daily newspaper.A.enhance B.enlarge C.extend D.expand
50.While writing a report,you have to write in a(n) _____ way.A.informal B.formal C.former D.foremost
51.They are _______ enough to get into universities.A.formal B.fortunate C.familiar D.fierce
52.Of swimming and football he much preferred the ____.A.former B.fortune C.figure D.formal
53.The little boy _____ his hiding place when he coughed.A.gave away B.gave up C.got away D.got in
54.Tomorrow we’ll have the final exam,so I have to ____ the books again.A.go over B.go on C.go for D.go through
55.It could be quite a few years before the product is _____ available.A.particularly B.generously C.generally D.individually

怎样鉴别NaoH+Hcl=Nacl+H2o 已经充分反应?
他们都是无色液体怎么样才知道,他们已经充分反映了?
帮帮忙配个平 Cu(oH)2+H2So4=?
NaoH+H2So4=?
说的稍微详细一点，就是如何在反应后用什么方法可以鉴别充分反映？

what kind of a() do you thik are the biggest on the earth?已经给出首字母a

已经知道矩阵A= 1 -2 4 -2 x -2 -4 -2 1
且A与对角矩阵B=diag{5,-4,y}相似,求x,y的值,并求正交矩阵Q使得Q^TAQ=B

_____/_____ _____ _____(已经)3 years since he ____ _____ ____(参军)

l _____ _________ ________(已经收集)all kinds of stamps for six year
这个是 根据汉语完成句子