Khi đốt cháy hoàn toàn 2 ancol no, đơn chức, mạch hở X, Y (MX<MY). Dẫn sản phẩm thu được qua bình đựng nước vôi trong dư thấy có 50 gam kết tủa và khối lượng dung dịc giảm 13,6 gam.

a.Công thức phân tử của hai ancol trên là

b. %khối lượng của X trong hỗn hợp là

Cho hình lập phương ABCDA'B'C'D'. M,N,P lầm lượt là trung điểm AB, BC, C'D'

Tính: a, \((\widehat{MN,C'D')}\)

b, \((\widehat{BD,A'D')}\)

c, \((\widehat{MN,AP)}\)

d, \((\widehat{A'P,DN)}\)

Cho hình chóp SABCD đáy hình thoi cạnh a,   \(\widehat{ABC}\) = 60^o. H là trung điểm AB, SH vuông với đáy, SH = \(\dfrac{a}{2}\)

Tính: a, \((\widehat{SD,BC})\)

b, \((\widehat{DH,SC})\)

1. I ................. the latest Harry Potter now. It is interesting!

A. am reading            B. have been reading C. have read D. had 

2. Human beings have great .................  on the rest of the world.

A. focus B. attention C. influence D. attraction

Rewirte

1: The psychologists who study the nature of sleep have made important discoveries. (Reduced relative clause)

2. John Quincy Adams, who was born on July 11th 1767, was the sixth president of the d United States. (Reduced relative clause)

3: Linda was the second student who answered this question correctly. (Reduced relative clause)

4: I never forget the garden. We met each other for the first time at this garden

5: Hans Lipperhey invented the telescope in 1608. He was a Dutch eyeglass maker. (combine to the sentences using Relative Clause)

Mark the letter A, B, C or D on your answer sheet to indicate the word or phrase that is OPPOSITE in meaning to the underlined part in each of the following questions.

1. It seems impossible to completely ban people from cutting down forests for wood and farming.

A. discourage

B. permit

C. promote

D. prohibit

2. We can help protect the environment by saving electricity and water.

A. spending

B. closing

C. promote

C. wasting

D. opening

I ................. the latest Harry Potter now. It is interesting!

A. am reading            B. have been reading C. have read D. had read

Chọn từ có phát âm khác

1. A. French                  B. school                  C. mechanic                  D. chemistry.

2. A. books                  B. meets                   C. skills                   D. stops

3. A. loved                   B. forced                  C. worked                  D. watched

Rewirte

1: The psychologists who study the nature of sleep have made important discoveries. (Reduced relative clause)

2. John Quincy Adams, who was born on July 11th 1767, was the sixth president of the d United States. (Reduced relative clause)

3: Linda was the second student who answered this question correctly. (Reduced relative clause)

4: I never forget the garden. We met each other for the first time at this garden

5: Hans Lipperhey invented the telescope in 1608. He was a Dutch eyeglass maker. (combine to the sentences using Relative Clause)