c d A___|_______\___________a | 1 \ | 1\ C B___|_________ \________b | 2 \ 3 a) Chứng minh a//b b) Tính C1,C2,C3 c) kẻ d là đường trung trực của AB, chứng minh d//a//b

What does the doctor recommend to eat?

What do happy people do? 

What kind of food will help people to keep fit and stay healthy?