根据课文填空（共10小题；每小题1分, 满分10分）

[A] Every year millions of people around the world die due to smoking. Every packet of cigarettes （66） __________poisonous chemicals that can result in lung cancer and heart disease. This costs countries a lot of money and causes great （67）__________to the welfare of the people. There are huge numbers of smokers in Asia. This is （68）_________we have chosen anti-smoking as the subjects of our ad campaign.

[B]The contemporary Olympics were first（69）__________in 1896, in Athens. It was a Frenchman, Pierre de Coubertin, who （70）__________the Olympics back to life. He dreamt that the Olympics would make it possible for people of all countries to live side by side in （71） __________. Now people all over the world are helping to （72） __________this dream. Among them are many well-known athletes.

[C]In scientific studies it has been shown that VR can be a good（73）_________for people who have social problems. In one case, a teenager who was（74）_________of talking and playing with his schoolmates was treated with VR. In the world created by RealCine, he became the captain of the Brazilian football team and scored the winning goal in a world cup final. This（75） ________him to become more confident around others.

0.5L 1mol/L FeCl₃溶液与0.2L 1mol/L KCl溶液中的Cl^-的物质的量浓度之比（　　）

A．5：2

B．3：1

C．15：2

D．1：3