Cho biểu thức C = \(\frac{x\sqrt{x}-1}{x-\sqrt{x}}-\frac{x\sqrt{x}+1}{x+\sqrt{x}}+\left(\sqrt{x}-\frac{1}{\sqrt{x}}\right)\left(\frac{\sqrt{x}+1}{\sqrt{x}-1}+\frac{\sqrt{x}-1}{\sqrt{x}+1}\right)\)

chứng minh C > 6

Giá trị nhỏ nhất của biểu thức  9 x 2 - 6 x + 5 đạt được khi x bằng ?

A. x = 1/2   

B. x = 1/3 

C. x = 3   

D. x = 4/3 

Tác dụng của biện pháp cày sâu dần kết hợp bón tăng phân hữu cơ và bón phân hóa học hợp lí ở cải tạo đất xám bạc màu?

A. Tăng độ phì nhiêu cho đất

B. Cung cấp chất dinh dưỡng và tăng vi sinh vật trong đất

C. Cung cấp đầy đủ chất dinh dưỡng cho đất

D. Làm tầng đất mặt dày lên, tăng độ phì nhiêu cho đất

Đẹp

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

Parents whose children show a special interest in a particular sport have a difficult decision to (47)______ about their children‟s career. Should they allow their children to train to become top sportsmen and women? For many children it (48) ______starting very young and school work, going out with friends and other (49) ______ have to take second place. It‟s very difficult to explain to a young child why he or she has to train for five hours a day, even at the weekend, when (50) _______ of his or her friends are playing.

Another problem is of course money. In many countries money for training is (51) ______ from the government for the very best young sportsmen and women. If this help cannot be given, it means that it is the parents (52) ______ have to find the time and the money to support their child‟s development- and sports clothes, transport to competitions, special equipment etc. can all be very expensive.

Many parents are understandably (53) _______ that it is dangerous to start serious training in a sport at an early age. Some doctors agree that young (54) _______ may be damaged by training before they are properly developed. Professional trainers, however, believe that it is only by starting young that you can reach the top as a successful sports person. What is clear is that very (55) _______ people reach the top and both parents and children should be prepared for failure even after many years of training.

Điền vào ô 49

A. wishes 

B. dreams 

C. satisfactions

D. interests