16．It's ten years _________ the scientist set out to discover the valuable chemical．（　�。�
A．whenB．thatC．beforeD．since

分析 自從這個科學(xué)家著手開始尋找有價值的化學(xué)物質(zhì)已經(jīng)有10年了．

解答 答案：D．根據(jù)選項(xiàng)since自從…，before在…前，when當(dāng)…時，再結(jié)合句意，自從這個科學(xué)家著手開始尋找有價值的化學(xué)物質(zhì)已經(jīng)有10年了，可知此處缺少了一個引導(dǎo)時間狀語從句的連接詞，故D 正確．句型It is/has been+一段時間+sincee…可翻譯為，自從…已經(jīng)多長時間…

點(diǎn)評 本題考查時間狀語從句的連接詞，在充分分析句型再結(jié)合語義的基礎(chǔ)上便能選出正確答案，同時要注意其他選項(xiàng)的意思

練習(xí)冊系列答案
相關(guān)習(xí)題

科目：高中英語 來源： 題型：完形填空

6．I was on a walk with a friend yesterday when I found an iPhone5s in a pile of snow．I picked it up and it still（36）C!I started looking through the name list and calling numbers to see（37）DI could figure out whose phone it was．（38）A，only one person answered and she didn't（39）Athe number that I was calling from．She gave a（n）（40）Bof"It is just so nice that you are trying to find out whose phone it is．"
Since that lady didn't know whose phone it was，my friend（41）Bthat we go back to the street and the （42）Cthat we found the iPhone5s in front of．I knocked on the door and two college-age people（43）D．They hadn't lost their phones，but as I told them the（44）Band mentioned some names on the name （45）C，the young man said that he also（46）Bthose names and it must be the phone of one of their friends．（47）A，both of the young men politely mentioned how （48）Bit was that I took the time to hunt for the owner．I really didn't have anything to say，because in my（49）DI was just doing the right thing．
I never considered（50）Athe phone-it wasn't mine．I immediately tried to find out the owner，because that is（51）Cwhat I would want someone to do if either I or any of my family members lost phones．
Eventually the owner （52）C，sincerely expressing a lot of thanks．I was very happy that the （53）Dpart was that I didn't say who I was-give my （54）A，or number．I strongly felt that the purpose of helping others is not for（55）D．Helping others is more than enough for me and it is the most endless joy of life．

36．A．phonedB．rangC．workedD．helped
37．A．howB．whyC．whenD．whether
38．A．UnluckilyB．HopefullyC．NaturallyD．Surprisingly
39．A．recognizeB．a(chǎn)cceptC．considerD．check
40．A．decisionB．opinionC．a(chǎn)nnouncementD．sentence
41．A．saidB．suggestedC．orderedD．warned
42．A．stationB．phoneC．houseD．gate
43．A．smiledB．a(chǎn)ppearedC．refusedD．a(chǎn)nswered
44．A．pointB．storyC．serviceD．offer
45．A．paperB．reportC．listD．information
46．A．forgotB．hadC．stoppedD．enjoyed
47．A．ThenB．InsteadC．HoweverD．Therefore
48．A．eagerB．wonderfulC．cleverD．kind
49．A．presenceB．a(chǎn)bsenceC．valueD．mind
50．A．keepingB．repairingC．buyingD．throwing
51．A．practicallyB．graduallyC．exactlyD．probably
52．A．got upB．picked upC．turned upD．kept up
53．A．worstB．strongestC．hardestD．best
54．A．nameB．handC．reasonD．idea
55．A．companionB．successC．freedomD．return

查看答案和解析>>

科目：高中英語 來源： 題型：選擇題

7．I have to go to work by taxi because my car ________ at the garage．（　　）
A．repairsB．is repaired
C．is being repairedD．is repairing

查看答案和解析>>

科目：高中英語 來源： 題型：選擇題

4．Turn on the TV quickly； a good play _________ on Channel 8．（　�。�
A．will showB．is being shownC．is shownD．has been shown

查看答案和解析>>

科目：高中英語 來源： 題型：選擇題

11．I think it will be quite a long time _______ Mike _______ from Canada．（　�。�
A．when； has returnedB．since； has returned
C．before； returnsD．after； returned

查看答案和解析>>

科目：高中英語 來源： 題型：選擇題

1．How about eight o'clock outside the cinemas？
That _____ me fine．（　�。�
A．fitsB．meetsC．satisfiesD．suits

查看答案和解析>>

科目：高中英語 來源： 題型：選擇題

8．_______is no hope that he can catch up with us．（　�。�
A．ItB．WhichC．ThereD．As

查看答案和解析>>

科目：高中英語 來源： 題型：選擇題

5．Now that the weather is so bad，the sports meet ___________．（　�。�
A．is to put offB．is put off
C．is to be put offD．will put off

查看答案和解析>>

科目：高中英語 來源： 題型：選擇題

6．Mr Smith is______ a good teacher_______ we all respect．（　�。�
A．such，thatB．such，asC．so，thatD．so，as

查看答案和解析>>

同步練習(xí)冊答案