Cho hàm số:  y − 1 − m x 4 − m x 2 + 2 m − 1 . Tìm m để đồ thị hàm số có đúng một cực trị

A. m< 0

B.  m < 0    v    m > 1

C. m ≤ 0    v    m ≥ 1

D. m> 1

a) Số số hạng là :

( 99 - 1 ) : 2 + 1 = 50 ( số )

Tổng là :

\(\frac{\left(99+1\right)\cdot50}{2}=2500\)

b) \(\frac{99\cdot\left(99+1\right)}{2}=4950\)

c) Số số hạng là :

( 102 - 2 ) : 2 + 1 = 51 ( số )

Tổng là :

\(\frac{\left(102-2\right)\cdot51}{2}=2550\)

Sự gia tăng dân số nhanh hiện nay ở nước ta đã tạo điều kiện thuận lợi cho việc

A. phát triển ngành công nghiệp sản xuất hàng tiêu dùng.

B. cải thiện chất lượng cuộc sống của nhân dân.

C. khai thác hiệu quả tài nguyên thiên nhiên.

D. mở rộng thị trường tiêu thụ.

Sự trao đổi chất ở người diễn ra ở mấy cấp độ ?

A. 4 cấp độ

B. 3 cấp độ

C. 2 cấp độ

D. 5 cấp độ

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

Schools in the United States have not always had a large number of libraries. As recently as 1958 about half of the public schools in the United States had no libraries at all. The (17)_______of public school libraries increased dramatically when the federal government passed the Elementary and Secondary Education Act of 1965, which provided funds for school districts to improve their education programs and facilities, including their libraries. (18) _______, many educators claim that since the legislation was passed federal spending has not increased sufficiently to meet the rising cost of new library technologies such as computer databases and Internet access.

Because the federal government provides only limited funds to schools, individual school districts (19)______ on funds from local property taxes to meet the vast majority of public schools tend to reflect the financial capabilities of the communities in which they are located. Districts in wealthy suburbs often have fully staffed libraries (20)________ abundant resources, spacious facilities, and curricular and instructional support. In (21) __________school districts in many poor areas house their libraries in ordinary classrooms or in small rooms. The libraries in such areas are generally staffed by volunteers, who organize and maintain books that are often out-of-date, irrelevant, or damaged.

Question 19

A. rely

B. come

C. go

D. stay

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

To preserve that _________, it was necessary to preserve the people that had created it.

A. civilize

B. civilization

C. civility

D. civil

The old man………..lives alone in that house is my uncle.

a. who

b. what

c. which

d. whom