Cho (O) và điểm A nằm ngoài đtr. Vẽ tt AB,AC và cát tuyến ADE, i là tđ DE. Tia Ci cắt (O) tại K. Cm:BK//AE

giả sử có các quần xã sinh vật sau: lá cây, bò,châu chấu,chim,gà,hổ,cáo,vi sinh vật
Xây dựng 3 chuỗi thức ăn từ các quần xã sinh vật nói trên

cà chua có 2n=24. Quan sát tế bào sinh dưỡng cà chua đang ở kì sau của quá trình nguyên phân. Số NST trong tế bào đó bằng bao nhiêu?

giải hpt: {x+2/y-2/=3
2x-/y-2/=1

make letter A,B,C or D to indicate the part that is incorrect
1. I started leaning How to play the football 3 year ago
A learning
B to play
C started
D the

giải ptr: a) 4 √x -x -3=0

cho tam giác ABC vuông tại A, kẻ đcaoAH. Biết AB=6cm, BH=3cm. Tính AH, AC, CH

2 ô tô cùng khởi hành cùng 1 lúc từ A đến B cách nhau 150km. Biết vận tốc ô tô thứ nhất lớn hơn vận tốc ô tô thứ 2 là 10km/h và ô tô thứ nhất đến B trước ô tô thưa 2 là 30 phút. Tính vận tốc của mỗi ô tô

Một xe khách và 1 xe du lịch khởi hành cùng 1 lúc từ HN đi HP. Xe du lịch có vận tốc lớn hơn vận tóc xe khách là 20km/h do đó đến HP trước xe khách là 25 phút. Tính vận tốc mỗi xe. Biết khoảng cách giữa HN và HP là 100km

cho ptr: x^2=2x-k+3
a. Giải ptr khi k=4

từ A nằm ngoài (O) vẽ 2 tiếp tuyến AB,AC. Vẽ dây BE của đường tròn (O) song song với AC,AE căt (O) tại D khác E;BD cắt AC tại S. Gọi M là trung điểm của đoạn DE.
a) CM: A,B,C,O,M cùng thuộc 1 đường tròn

Question 1. Spending twelve hours on a plane isn't a very...prospect.
D. attraction
A. attractive
B. attract
C. attractively
Question 2. We're reading a.....book this week.
A. difference
B. differently
C. differ
D. different
C3 The song was...with people from my father's generation.
A. popularity
C. popularize
D. popularly
B. popular
C4 It's .....to take more than the recommended dose.
A. endanger
B. danger
C. dangerous
D. dangerously
Occasions.
Question 5. I have a suit for....occasions
A. special
B. specialize
C. specially
D. specialization
Question 6. The jury has to....whether a person is guilty or innocent of a crime.
B. decision
C. decisive
D. decisively
A. Decide
Question 7. It's an old house, and it needs a lot of....
C. attend
D. attentively
A. attentive
B. attention
Question 8. My younger son has a very vivid.....
C. imagine
A. imaginatively
B. imagination
D. imaginative

Question 30: The company had sent an advertisement to the newspaper when
they realized they'd mistyped the salary they were offering for the position.
Luckily, they ……the newspaper to correct their mistake before they printed it.
B. must have asked
A. could have asked
C. were able to ask
D. might have asked
Question 31: The sun appears to be shining on your computer screen…… I close the curtains for you as it…..you?
B. Will - were disturbing
A. Let-has disturbed
C. Do- is disturbing
D. shall - must be disturbing
Question 33: Sam….his collection because she needs money to buy clothes.I can imagine his mother's anger if he does.
A. may have to sell
B. may have sold
C. could have sold
D. must have sold
Question 36: You…be rich to be a success. Some of the most successful people I know haven't got a penny to their name.
A can’t
B. shouldn't
C.don’t have to
D mustn’t

Question 21: Smith had a lucky escape. He …. killed.
A. should have been
B. would have been
D. could have been
C. must have been
Question 22: There was plenty of time. She_
A. mustn't have hurried
B. must not hurry
C. needn't have hurried
D. couldn't have hurried
Question 24: He spent all that money last week. He….so much.
A. didn't need to spend
B. shouldn't spend
D. didn't have to spend
C. needn't have spent
Question 25: Mike painted his bedroom black. It looks dark and dreary. He…….
a different colour.
A. must have chosen
B. had to choose
C. should have chosen
D. could have been choosing
Question 27: " Why wasn't your boyfriend at the party last night?"
_”He….the lecture at Shaw Hall. I know he very much wanted to hear the speaker.”
A. may have attended
B. was to attend
D. can have attended
C. should have attended

Question 12: Changes have been made in our primary schooling program. As a
result, young children …… do homework anymore.
A. couldn't
B. needn't
C. oughtn't
D. havent
Question 13: Although nobody can prevent you from spending your own money, you.. save for a rainy day
B. better
A. would better
C. had better
D. would rather
Question 14: Since they aren't answering the phone, they _their house.
A. need have left
B. can't have left
C. must have left
D. should have left
Question 15: Peter was out of town that Sunday. Therefore, he….the crime.
A. couldn't have committed
B. needn't have committed
C. must have committed
D. would have not committed
Question 16: When you got lost in the forest you….. very frightened
A. should have been
B. couldn't have been
C. can't have been
D. must have been
Question 17: You look so tired! You….out too late last night.
A. must have been
B. had been
C. had to be
D. should have been
Question 18: Adrian got surprisingly high grades in the final exam.He…his lessons very carefully.
A. would have revised
B. must have revised
D. can't have revised
C. needn't have revised
Question 19: You…to your teacher like that. It was very rude.
A. wouldn't have talked
B. must have talked
C. needn't have talked
D. shouldn't have talked
Question 20: My purse……at the station while I… for the train
A. must have been stolen/was waiting
B. should have stolen/had been waiting
C. will be stolen/am waiting
D. had to steal/would be waiting

Question 54. We should stop and prevent doing what can do serious damage to
by conserving rare plants and animals and by stopping the
Our
pollution.
B. environmental
A. environment
C. environmentalist
D. environs
Question 55. Whether or not we go to Mexico for our holiday
on the cost.
A. depends
B. indeperndence
C. dependability
D. independently
Question 56. We
the possibility that it could have been an accident.
B. eliminatory
A. elimination
C. eliminative
D. eliminated
Question 57. You can use a shredder to
old bank
statements.
A. destroy
B. destructive
D. destructor
C. destruction
Question 58. Doesn't all this violence on TV
you?
A. disgusting
D. disgustedly
B. disgust
C. disgustful
Question 59. Between 1076 and 1779, Quoc Tu Giam was a place to
the talented for the nation.
D. production
A. product
B. produce
C. productively
Question 60. A group of four teachers were delegated to
the
school at the union conference.
A. representable
B. represent
D. representative
C. representation

1. She became deeply ……. when her husband died
A depress
B depressed
C depression
D depressing
2 Safety regulations are being …. by company managers in the drive to increase profits
A ignoring
B ignored
C ingnorance
D ingnorant
3 He has a very good… with his uncle
A relate
B relationship
C relative
D relatively

1I’ve seen the film “Casabalanca” so many time that I …….. a lot of it by heart
A.knowledgeable
B.knowledgeably
C.knowledge
D.know
2 he had all the fences around his home ……
A. electricity
B electrified
C electric
D electrically

Mars is called the Red planet due to its.....surface
A red
B redder
C reddest
D reddish

There have been many UFO.... reported
A sights
B signs
C signals
D sightings