Cho tam giác ABC vuông tại A có AB =6cm, bc = 10cm đường cao ah

a) chứng minh ah^2=bh.ch

  Hoạt động của Đông Kinh nghĩa thục ở Bắc Kì năm 1907 và hoạt động của cuộc vận động Duy Tân ở Trung Kì năn 1908 có những điểm tương đồng nào?

Some of the public would like the seven new Earth-like planets to be named _______ famous movies.

A.before                          B. out                          C. with                        D. after

giải thích nx ah

viet lai cau sao cho nghia k doi ( GIẢI THÍCH NX AH )

1.I wrote this book in three weeks

-->It took...................................................

2.She can't afford to go on holiday

-->She hasn't got............................................

3.They missed the flight.

-->When they...................................................

4.We wished we hadn't bought this house

-->He regretted..................................................

5.You will catch a cold if yoy don't keep your feet dry

-->Unless....................................................................

6.He mended thw washing machine for me

-->I had the.................................................

7.He is such a slow speaker that he get bored

-->He speaks........................

8.He said that he didn't steal your pen

-->He denied.........................................

9.Because I don't khow Japanese, I can't apply for the position

-->If I knew..........................................................................

10.It's ages since they heard from her

-->They.................................................

GIẢI THÍCH NX AH

Bai 1: Re­write the sentences in such a way that they mean almost the same as those printed before them.
1/ She is too young to see this film.
=> She is not old................................
2/ He drives carelessly, so he usually has accidents.
=>He is such........................................................
3/ ' Why don't we stop destroying forets?"
=> I suggested...........................................
4/ Mr. Tam is the most careful worker in the factory.
=> Nobody.......................................................
5/Why don't you give up smoking?
=> If..............................................................
6/ It's ages since we last met him.
=> We haven't...............................
7/ She'd better improve her English.
=> I suggest........................................
8/ " I'm sorry. I'm late" I said to him.
=> I apologized....................................
9/ The room is too old to be used.
=> The room needs..............................
10/ It takes us only five minutes to brush teeth every morning.

GIẢI THÍCH

When the air is dirty it has become polluted. Air (1) _______ is made up of gases, dust, odors, particles, smoke, fumes, and other substances which can be harmful to humans, animals, plants, and all living organisms. The air is (2)_______ and unclean.

Air pollution affects the Earth's atmosphere. The atmosphere of the Earth is like a blanket of air which protects all life. Without the atmosphere, life would not exist. The atmosphere protects living organisms from the heat of the Sun during the day, and at night it prevents the warm air from escaping. Basically, the atmosphere helps keep the living things(3) _______ Earth from burning up or freezing.

The pollution in the air, though, may affect this 'blanket' and becomes harmful to life on Earth. The substances in the air causing the dirty air (4)_______called pollutants. (5)_______examples of pollutants may include gases called carbon monoxide, nitrogen oxide, hydrocarbons, and others. There may also be sand, dust particles, and other substances that evaporate and become pollutants.