Xét các nguyên tố thuộc các nhóm A. Trong cùng một chu kì, khi đi từ trái sang phải, độ âm điện của các nguyên tử biến thiên thế nào (không xét các khí hiếm) ? Giải thích.

Choose the letter A, B, C or D to complete the passage below

Let’s ________ (6) at this picture. It’s the Great Pyramid of Giza. It __________ (7) a symbol of Egypt and the last of the ancient Seven Wonders of the World. It is located on the Giza, near the modern city of Cairo. It is __________ (8) and the oldest one among the three pyramids of the Giza Pyramid Complex. Scientists believe that this pyramid was built ___________ (9) a period of 10 to 20 years. For over 3,800 years, the Great Pyramid of Giza stood tall as the world’s tallest structure. In the pyramid, there is the _________ (10) of Khufu, the Fourth Dynasty Egyptian pharaoh.

Question 9:

A. in

B. on

C. over

D. at

f(0) = 1

f(1) = 2018

f(-1) = 0