There are many countries in the world where the water supply is not sufficient for the growing population, and other sources have to be found. Even the sea is used in some countries, but the problem of removing the salt is a severe one. Sea water can be used for a supply of drinkable water if it can be separated from the salt dissolved in it.

A．While dieting, you should ask the doctor so that you can lose your weight quickly.
B．Plan meals means to have some foods you like and take them as your daily eating habits.
C．When you have lost your weight, you can have some coffee and tea without sugar or cream.
D．As you are dieting, don’t forget exercise.