Biết rằng phương trình 2 − x + 2 + x − 4 − x 2 = m  có nghiệm khi m thuộc [a;b] với a , b ∈ ℝ . Khi đó giá trị của biểu thức T = a + 2 2 + b  là

A.  T = 3 2 + 2  

B.  T = 6  

C.  T = 8  

D.  T = 0

We are talking about the writer ____ latest book is one of the best-sellers this year

A. which

B. whose

C. who

D. whom

Khi tia sáng khúc xạ từ môi trường có chiết suất tuyệt đối  n 1  với góc tới i, sang môi trường có chiết suất tuyệt đối  n 2  góc khúc xạ r. Hệ thức đúng là

A.  sin i sin r = n 2 n 1

B.  sin i sin r = n 1 n 2

C.  cos i cos r = n 2 n 1

D.  cos i cos r = n 1 n 2

whose

1/ on / in

2/ of

3/ on

4/ at / at

5/ in

6/from/ untill

7/ at

8/ of

đề đâu

Cho X, Y là hai axit cacboxylic đơn chức (M_X < M_Y); T là este ba chức, mạch hở được tạo bởi X, Y với glixerol. Cho 23,06 gam hỗn hợp E gồm X, Y, T và glixerol (với số mol của X bằng 8 lần số mol của T) tác dụng vừa đủ với 200 ml dung dịch NaOH 2M, thu được hỗn hợp F gồm hai muối có tỉ lệ mol 1 : 3 và 3,68 gam glixerol. Đốt cháy hoàn toàn F cần vừa đủ 0,45 mol O₂, thu được Na₂CO₃, H₂O và 0,4 mol CO₂. Phần trăm khối lượng của T trong E có giá trị gần nhất với giá trị nào sau đây? 

A. 29. 

B. 35. 

C. 26. 

D. 25. 

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

After two decades of growing student enrollments and economic prosperity, business schools in the United States have started to face harder times. Only Harvard's MBA School has shown a substantial increase in enrollment in recent years. Both Princeton and Stanford have seen decreases in their enrollments. Since 1990, the number of people receiving Masters in Business Administration (MBA) degrees, has dropped about 3 percent to 75,000, and the trend of lower enrollment rates is expected to continue.

There are two factors causing this decrease in students seeking an MBA degree. The first one is that many graduates of four-year colleges are finding that an MBA degree does not guarantee a plush job on Wall Street, or in other financial districts of major American cities. Many of the entry-level management jobs are going to students graduating with Master of Arts degrees in English and the humanities as well as those holding MBA degrees. Students have asked the question, "Is an MBA degree really what I need to be best prepared for getting a good job?" The second major factor has been the cutting of American payrolls and the lower number of entry-level jobs being offered. Business needs are changing, and MBA schools are struggling to meet the new demands.

The phrase "two decades" in line 1 refers to a period of _______.

A. 10 years

B. 20 years

C. 50 years

D. 100 years

Mark the letter A, B, C, or D to indicate the word that differs from the rest in the position of the main stress in each of the following words.

A. primitive 

B. continuous

C. familiar

D. particular

Mark the letter A, B, C, or D to indicate the correct answer to each of the following sentences.

Janet: "Do you feel like going to the cinema this evening?"  -Susan: "_______ ."

A. I don't agree, I'm afraid

B. That would be great

C.  I feel very bored

D. You're welcome