H=\(\left(\frac{x+x^3}{1-x^2}-\frac{x-x^3}{1+x^2}\right):\left(\frac{1+x}{1-x}-\frac{1-x}{1+x}\right)\)

RÚT GỌN PHÂN THỨC TRÊN HỘ MÌNH NHÉ (^-^)

British space scientists are planning to join the American in the race to find evidence of life on (1)_______ planets. Alan Penny and his team at the Rutherford Appleton Laboratory have designed a telescope that is 40 times more powerful than Hubble. Known as ‘Darwin’, his telescope could tell if planets 50 (2) _______ years away have any kind of life on them. Two days (3) _______, NASA scientists had shown a proof that one of Jupiter’s moons could support life, Penny announced that his telescope may be included in a European Space Agency mission. The Darwin project, with a (4)_______ of 500 million, is on a short list of two proposals. If approved it will probably be (5)_______ around 2015, its destination somewhere between Mars and Jupiter. The blueprint is actually for five telescopes positioned 50 meters apart in space, slowly circling a (6)_______ processing station. The combined data from these telescopes would build up a full picture of a planet, picking out faint images that have never been seen before. Darwin would not be able to take detailed photographs of the planets it (7) _______, but Penny believes a second- generation telescope could be sent up to do this. He claims it is worthwhile mapping the universe around our (8) _______ galaxy, even though these planets lie (9)_______ our reach for the moment. The European Space Agency will make its decision (10) ______ Darwin within three years.

1. A. another B. other C. others D. the other

2. A. light B. lighten C. lightening D. lighting

3. A. following B. after C. next D. later

4. A. price B. schedule C. charge D. budget

5. A. driven B. fetched C. launched D. taken

6. A. central B. centre C. middle D. heart

7. A. invents B. searches C. discovers D. looks

8. A. alone B. same C. one D. own

9. A. out B. toward C. beyond D. over

10. A. of B. on C. about D. with

Các bạn điền đáp án vui lòng trả lời tại sao lại chọn đáp án đó cho mình nhé

Cho tam giác ABC, đường cao AH. Trên nửa mặt phẳng chứa A bờ CB lấy các điểm D và E sao cho tam giác ABD và ACE vuông cân tại B và C. Trên tia đối tia AH lấy K sao cho AK=BC. Chứng minh rằng:

a) Tam giác ABK= Tam giác BCD

b) CD vuông góc với BK ; BE vuông góc với CK

c) Ba đường thẳng AH, BE, CD đồng quy

CẢM ƠN BẠN ĐÃ GIÚP ĐỠ

Cho tam giác ABC (AB<AC) lấy D thuộc AB, E thuộc cạnh AC sao cho BD=CE .Gọi M,N theo thứ tự là trung điểm của BC, DE

a) CMR: MN song song với tia phân giác góc A

b) Đường thẳng MN cắt AB, AC tại K và I .CMR: Tam giác AIK là tam giác cân

c) Trên tia AB, AC lấy các điểm P và Q sao cho AP+AQ = m không đổi. CMR: Đường trung trực của PQ luôn đi qua 1 điểm cố định.

CẢM ƠN VÌ ĐÃ GIÚP

Cho tam giác ABC vuông tại A, đường phân giác BE. Kẻ EK vuông góc với BC (KBC). a. Chứng minh EA = EK. b. Gọi H là hình chiếu của C trên BE. Vẽ điểm D sao cho H là trung điểm của DE. Chứng minh góc CDE bằng góc CED, từ đó so sánh góc CDE và góc AEB? c. So sánh CD và CB? d. Tìm điều kiện của tam giác ABC để góc DCA = 2.góc ACB?

how/enjoyable/it/be/take part /this party

Tại sao công cụ bằng đồng dần được thay thế công cụ bằng đá ?

mọi người giúp em với !

DỊCH HỘ MÌNH NHÉ

POPPY DAY POPPY DAY , 11 November, is the day when people in Britain remember the soldiers that died in the First World War (1914 – 1918), the Second World War (1939 – 1945) and all other wars since. The first Poppy Day was in 1921. The First World War had ended three years earlier, but it was still very difficult, even impossible, for ex-soldiers in Britain to find employment. So some of them started making and selling red paper poppies. They gave the money that they raised to ex-soldiers who were disabled or unemployed, and to the families of soldiers who had died. The choice of flower was significant. During the war, the soldiers had noticed poppies growing every year on the battlefields in Belgium and the north of France. A well – known poem from that time, written by a Canadian soldier, begin with the lines: In Flanders* fields the poppies blow Between the crosses, row on row, That mark our place*; … In the days leading up to Poppy Day, about 32 million people in Britain buy and wear small poppies. Some people choose to wear white poppies because they think that white symbolizes peace. Then, at 11 a.m. on 11 November (at the moment when the First World War ended) there’s a two – minute silence. Many people stop and think quietly about the soldiers who died. There are ceremonies at war memorials in towns and villages all over the country. The most important ceremony is in London, when the Queen and the Prime Minister lay wreaths of poppies at the Cenotaph, a monument to soldiers who died in battle. *(Flanders ­= the north of Belgium; our place = our graves)