Tử Linh's Profile

Bài 3: cho hình chóp S.ABCD có đáy ABCD là hình thoi O, cạnh a,  = 60^o; SO $\perp$ (ABCD), SO = $\frac{3\mathrm{a/}}{4}$.

Xác định và tính thiết diện của hình chóp khi cắt bởi mp (a) qua AD vuông góc với (SBC).

1. A. plants          B. cup             C. crop           D. cupboard 

2.A. bad              B. double        C. doubt          D. bright 
3, A. psychology      B. potato        C. paper          D. possible 
4. A. fobbed          B. crab          C. club           D. dumb 
5. A. recipe          B. special       C. repeat         D. receipt 
6. A. combine         B. problem       C. lamb           D. Dublin 
7. A. pneumonia       B. equipment     C. explosion      D. surprise 
8. A. obey            B. tomb          C. table          D. blade 
9. A. program         B. people        C. psalm          D. pipe 
10. A. debt/det/      B. able          C. football       D. trouble 
II/   Choose   the   word   whose   underlined   part   has   a   different   pronunciation   from   th e   others   in   each 
group: 
1/A. conservation         B. nation             C. mention           D. question 
2/ A. medicine            B. protect            C. species           D. never 
3/ A. variety             B. pattern            C. vary              D. back 
4/ A. painted             B. protested          C. fetched           D. eroded 
5/ A. pollute             B. develop            C. constant          D. provide 
6/ A. must                B. natural            C.  hunt             D. fun 
7/ A. scientist           B. million            C. police            D. medical 
8/ A. sorry               B. monthly            C. sky               D. usually 
9/ A. cups                B. photos             C. failures          D. always 
10/ A. teach              B. much               C. school            D. choice 
III/ Choose the word whose main stress is placed differently from the others in each group: 
1/A. vegetation           B. eliminate          C. disappearance D. intonation 
2/ A. photo               B. rapid              C. pattern           D. about 
3/ A. environment         B. understanding      C. population        D. conservation 
4/ A. impossibly          B. especially         C. naturally         D. importantly 
5/ A. medical             B. pollutant          C. imprison          D. protective 
6/ A. conserve            B. disease            C.  wildlife         D.  expand 
7/ A. illness             B. slowly             C. spoken            D. police 
8/ A. correction          B. motorway           C. addition          D. erosion 
9/ A. damage              B. pollute            C. defense           D.  erode 
10/ A. power              B. autumn             C. allow             D. order 

1.   I didn't go into business with Sam. If I had gone business with him, I would have become a success. 
2.   We got to the station in time to catch the train. If we....................(miss), it We ................ (be) late for 
    the meeting. 
3.   Mary and I weren't able to go on a honeymoon We.............. (can/ go) away if my father ……. (not get) 
     sick. 
4.   I took a taxi to the hotel but the traffic was very bad. It .................... (be) quicker if I.................... 
     (walk) 
5.   It's good that you reminded me about Ann's birthday. I..............(forget) if you ……… (not remind) 
    me. 
6.   The view was wonderful. If I  ……….            (have) a camera, I ……..          (take) some photographs. 
7.  Unfortunately, I didn't have my address book with me when I was in New York. If I …… (have) your 
     address, I ……….. (send) you a postcard. 
8.   We ………… (may/ be) at the airport for hours, if we ………                          (not know) that the flight was 
     delayed. 
9.   The accident was your fault: If you ……… (drive) more carefully, it ………….. (not happen). 
10. If you ………. (tell) me you needed money, ………. (can/ lend) you some.

admire, reduce, cut, find, remember, listen, lose, make, miss, take, protect, wake up, complete, be, avoid. 
    1.  I am going  on a diet …to lose………. weight. 
    2.  The President has a team of bodyguard ……….. him. 
    3.  Mike hid behind the tree ………… by his friends. 
    4.  We took off our boots ………. the floor dirty. 
    5.  We wrote Betty's name on the calendar ………… her birthday. 
    6.  The government took these measures …………. crime. 
    7.  The staff are working at weekends ………… the project in time. 
    8.  She gave up her job ………….. care of her mother. 
    9.  I shut the door quietly ………… the baby. 
    10. She took a bus ……… late. 
    11. He turned on the radio ………… to the news. 
    12.After dinner we drove to the top of a hill outside the city ………. the sunset. 
    13. Leave early ……….. the bus. 
    14. I carried the knife carefully ………. myself. 
    15. We went to the countryside ………… being disturbed by the noise of the city. 

1/ If I (be) _______ you, I (help) _______ her now. 
2/ If she (be) _______ late, she will be punished. 
3/ I could have understood him if he (speak) _______ more slowly. 
4/ What (you/do) _______ if you (be) _______ a billionaire? 
5/ You didn’t pay attention to the teacher’s explanation. If you (pay) _______ more attention, you (do) 
_______ the exam well. 
6/ She’s waiting for her uncle to come back from Ho Chi Minh city. If her uncle (come) _______ home, 
she (have) _______ a lot of presents. 
7/ Sang is a naughty boy and often makes fun ofhis classmates. If he (start) _______ a joke, someone (cry) 
_______ bitterly. 
8/ Chung wanted to buy some presents for his younger sister but he couldn’t. If he (afford) _______ to 
buy, her younger sister (be) _______ happy to greet a new year. 
9/   He   is   never   willing   to   help   poor   people.   If   he   (do)   _______   something,  the   earth   (stop)   _______ 
moving. 
 10/ I didn’t know her mother was ill. If I (know) _______ that, I (come) _______ to visit her.