分类：教育/科学-学习帮助
问题：英语问题21.Onlyaknifeandfork_____ont 
1.ly a knife and fork _____ on the table.There is nothing else.A.are     B.are left    C.is     D.was为什么选C？为什么用单数？2.Last year he bought the house _______.为什么用cheap，不用cheaply？3.Clever students need never work hard,_____?A.do they    B.need they选哪个？为什么？4.All of t1.ly a knife and fork _____ on the table.There is nothing else.A.are     B.are left    C.is     D.was为什么选C？为什么用单数？2.Last year he bought the house _______.为什么用cheap，不用cheaply？3.Clever students need never work hard,_____?A.do they    B.need they选哪个？为什么？4.All of the flowers now raised here have developed from those ______ in the forest.A.once they grew      B.ther grew once     C.that once grew     D.once grew为什么选C不选D？是什么原因？5.They are likely to travel more and want more education,______,many more jobs are acailable  in these services.填therefore？还是meanwhile？能把句子意思解释一下吗？6.Rorbet is said ______ abroad, but I don't know what country he studied in.A.to have studied      B.to be studying    C.to have been studying选A？为什么其他几个不能选啊？
回答：1.Only a knife and fork _____ on the table.There is nothing else.A.are B.are left C.is D.was选C .在英语中，当不可分割的两个词用在一起时，表示一个整体，谓语用单数.                                                                  2.Last year he bought the house _______.cheap修饰house, 做定语，便宜的房子.不用cheaply，因为如果用cheaply就修饰bought了，便宜的买了，说不通，而且副词也不能修饰名词house.3.Clever students need never work hard,_____?A.do they B.need they选Ｂ．带情态动词dare或need的反意疑问句，疑问部分常用 need （dare ） +主语。例如：We need not do it again, need we ? 我们不必重做一遍，是吗？He dare not say so, dare he? 他不敢这样说，是吗？当dare, need 为实义动词时，疑问部分用助动词do + 主语。例如：She doesn't dare to go home alone, does she? 她不敢独自回家，是吗？4.All of the flowers now raised here have developed from those ______ in the forest.A.once they grew B.ther grew once C.that once grew D.once grewthat后面引导定语从句，修饰those,Ｄ中没有that,又出现了一个动词grew，这样句子就有了两个动词，语法上说不通．5.They are likely to travel more and want more education,______,many more jobs are acailable in these services.题中的acailable写错了，应该是available,　空白处应该是meanwhile,整句意思为：他们有希望去旅游并接受更多的，同时，这些服务的工作都还空缺着．6.Rorbet is said ______ abroad, but I don't know what country he studied in.A.to have studied B.to be studying C.to have been studying选A　据说Rorbet 曾在海外学习，但是我并不知道他在哪个国家学习．从后面看，studied为过去时，说明Rorbet 现在并不在国外学习了．所以只能选Ａ．其他选项为进行时态，不合题意．