Marshall's textbook "principles of economics" became the standard for teaching of that subject until 1940s определить видовременную форму глагола и укажите их инфинетив

Became - Past Simple, инфинитив - to become

 A person who is full of energy, has an attractive appearance and is in good mood deserves everybody’s admiration and is always welcomed in companies. Moreover, this person is contented with himself and is open for numerous opportunities that life gives to him.

What is a secret of such a success? The answer lies on the surface. Don’t be lazy and string yourself up to keep fit. May be you should change your entire lifestyle that is a hard thing to do, but very soon you will feel a positive effect. Don’t be discouraged! The scientists have approved that a person need only twenty one days to get used to something. So, you have only three weeks for discomfort to endure. And perhaps it will not be hard for you at all. As gratitude your body will grant you with lightness and beauty, health and high spirits.

What rules are you to obey to look wonderful? Firstly, you should get rid of bad habits. Smoking and drinking alcohol don’t give you any benefit. Smoking ruins your lungs, badly influences the complexion, teeth and hair conditions. Alcohol kills neurons in your brains. You will say that these things help you to relax and have fun. Don’t worry, when you stop smoking and drinking your organism will allocate the hormones of joy itself without any doping.

The second important thing is to have enough rest. You need at least seven hours of sleeping to rejuvenate your body. It’s better if you go to bed early in the evening and wake up together with the sun. The bedroom should be airy and cool.

Physical activity is very important for keeping fit. Attending gym will make you a lot of good, including strong muscles and physical endurance. Besides going to special clubs you can simply ride a bicycle, run, swim, play football and volleyball or go in for any other sport you prefer.

Morning exercises and water procedures are ideal for the beginning of the day. It will wake you up and will result in muscle tone. Don’t neglect stretching. It will keep your body young for a long time and will slow down the aging process.

Spend more time in the fresh air. Big cities with their gassy atmosphere contribute headaches and various diseases. Try to break free, walk in a park or go to a countryside from time to time to get a breath of oxygen.

And, the last, the most important thing to do is to eat right. Without it, all other things are practically useless. It is the main and the most difficult thing to do to keep fit. There are several tips that will help you to begin eating healthy food. Remember that breakfast should be hearty. You can eat as much as you want. Everything that you eat for breakfast will be processed into energy during the day. Eggs, porridge, cheese, fruit and nuts are perfect to have in the morning. Try not to drink too much coffee. It awakens the appetite and as a result you will eat much more food than without it. Drink pure water with lemon. For breakfast you may help yourself with dark chocolate or pastry.

Lunch should consist of meat and vegetables. It can be either a soup or a stew; it’s up to your taste.

Supper should take place not less than four hours before going to bed. It should consist of light products with low calories. If you are not very hungry, just drink a glass of kefir without sugar.

Following these rules you will improve your life’s quality. You will not only feel much better but also look great. A positive spirit is also a path to success. Don’t hold a grudge against anybody, don’t be envious and jealous. Try not to be nervous and I am sure you will cope with keeping fit.

Present Perfect - The children have drunk milk (already).

Past Simple - The children drank milk (yesterday).

Past Progressive - The children were drinking milk (while I was brushing my teeth) .

Past Perfect - The children had drunk milk (by the time I came into the kitchen).

Future Simple - The children will drink milk (tomorrow).

Future Progressive - The children will be drinking milk (this time tomorrow).

Future Perfect - The children will have drunk milk (by 8 o`clock).

в скобках даны продолжения предложений для уточнения времени.