Cho cấp số nhân ( u n ) với công bội q < 0 và  u 2 = 4 , u 4 = 9  . Tìm u 1

A.  u 1 = − 8 3 .

B.  u 1 = 8 3 .

C.  u 1 = − 6.

D.  u 1 = 6.

Số thập phân gồm mười một đơn vị, mười một phần nghìn viết là:

A. 11,110

B. 10,011

C. 11,011

D. 11,101

Choose the word or phrase among A, B, C or D which best fits each gap of the passage.

We need energy to live and work. Our major source of…(36)……….is oil. Oil is one kind of fossil fuel. The amount of fossil fuel in the world is……(37)….Therefore, we must save it, and the same time, we must find new sources of energy. Geothermal heat and nuclear power are……(38)….sources of energy. They can give us electricity. Other alternative sources are the sun, waves and water. The sources are not only …(39)……and available but also clean and safe for the…(40)…People should develop and use them more and more in the future.

Question 39:

A. unlimited

B. harmful

C. polluted

D. dangerous

Trong không gian cho tam giác ABC vuông tại A, AB=2a và ACB = 30 ° . . Thể tích V của khối nón nhận được khi quay tam giác ABC quanh cạnh AC là

A.   V = 8 3 πa 3 3 .

B.  V = 3 πa 3 .

C.  8 3 πa 3 9 .

D.  πa 3 .

Read the passage and answer the questions

(1) __________ near the southern margin of the Red River Delta, the Trang An Landscape Complex is a spectacular landscape. Exploration of caves at different altitudes has revealed archaeological traces of human activity over a continuous period of more (2) __________ 30,000 years. They illustrate the occupation of these mountains by seasonal hunter-gatherers and how they adapted (3) ___________ major climatic and environmental changes, especially the repeated inundation of the landscape by the sea after the last ice age. The story of human occupation continues through the Neolithic and Bronze Ages to the historical era. Hoa Lu, the ancient (4) ___________ of Viet Nam, was strategically established here in the 10th and 11th centuries AD. The property also contains temples, pagodas, paddy-fields and small villages.

Question 2:

A. that

B. then

C. this

D. than