Read the passage and choose the correct answer (A, B, C or D).

Earth, our beautiful home planet, is the only astronomical object to accommodate life (23) . . . . . we know it. Scientists believe Earth was (24) . . . . . approximately 4.5 billion years ago. It is the fifth-largest (25) . . . . . in our solar system. Its equatorial diameter is about 12,074 kilometres. Earth is the third-closest planet to the sun. The distance from Earth to the sun is roughly 149,600,000 kilometres. It (26) . . . . 365,3 days for Earth to obit the sun, and 24 hours to rotate on its axis. The surface temperature ranges from -88 to 58° C. Nearly 70 percent of Earth’s surface is covered by ocean, (27) . . . . has an average depth of about 4 kilometres. In 2015 it was estimated that 7,3 billion humans are living on Earth.

Quesstion 25:

A. system

B. planet

C. star

D. sun

Cho tam thức bậc hai f x = a x 2 + b x + c , a , b , c ∈ ℝ , a ≠ 0  có hai nghiệm thực phân biệt x 1 , x 2 .  Tính tích phân I = ∫ x 1 x 2 2 a x + b 3 . e a x 2 + b x + c d x  

A.  I = x 2 − x 1

B.  I = x 2 − x 1 4

C. I = 0

D.  I = x 2 − x 1 2

Bài thơ Bài ca ngắn đi trên bãi cát được viết bằng chữ gì?

A. Hán 

B. Nôm 

C. Chữ Quốc ngữ 

D. Chữ khác