A blood sample is sent to a physical laboratory.

It’s difficult (5)…………………..us to calculate.

Read the passage, and then choose the best answers.

Each country has many good people who take care of others. For example, some of students in the United States often spend many hours as volunteers in hospitals, orphanages or homes for the elderly. They read books to the people in these places, or they just visit them and play games with them or listen to their problems.

Other young volunteers go and work in the homes of people who are sick or old. They paint, clean up, or repair their houses, do the shopping. For boys who don’t have fathers,

there is an organization called Big Brothers. College students and other men take these boys to basketball games or on fishing trips and help them to get to know things those boys usually learn from their fathers.

Each city has a number of clubs where boys and girls can go and play games. Some of these clubs show movies or hold short trip to the mountains, the beaches, museums, or other places of interest. Most of these clubs use a lot of students as volunteers because they are young enough to understand the problems of younger boys and girls.

What do volunteers usually do to help those who are sick or old in their homes?

If people want to keep (6) …………….., they should remember that everyone should have between 1600 and 2500 calories a day.

But how many calorie should we (4) ………………a day to stay in shape?

So besides studying, we should do some (9)………….., play sports or do the housework, such as cleaning the floor, cooking etc.

We get calories (7) …………….the food we eat.

What do they help boys whose fathers do not live with them?