I / have / toothache / so / I / have to / see / dentist.

A. We should keep our bodies warm to avoid flu or a cold.

B. We should to keep our bodies warm to avoid flu or a cold.

C. We should keeping our bodies warm to avoid flu or a cold.

D. We should keep our bodies warm to avoiding flu or a cold.

A. Get enough rest helps you concentrate at school.

B. Getting enough rest helps you concentrate on school.

C. Get enough rest helps you concentrate on school.

D. Getting enough rest helps you concentrate at school.

A. The doctor is asking Huy some questions about his health problems.

B. The doctor asking Huy some questions about his health problems.

C. The doctor is asking Huy some questions about their health problems.

D. The doctor is asking Huy any questions about his health problems.

A. I have a toothache yesterday because I ate many sweets.

B. I had a toothache yesterday because I ate many sweets.

C. I have a toothache yesterday because I eat many sweets.

D. I had a toothache yesterday because I eat many sweets.

A. I like but coffee, I don’t like tea.

B. But I like coffee, I don’t like tea.

C. I like coffee, but I don’t like tea.

D. I like coffee, I don’t like tea, but.

A. It am easy to get flu. We should try to keep clean more.

B. It is easy to get flu. We should to try to keep clean more.

C. It is easy to get flu. We should try to keep clean more.

D. It is easy to get the flu. We should try to keep clean more.

A. When I was ten, I began to play football.

B. When I was ten, I begin to play football.

C. When I am ten, I began to play football.

D. When I was ten, I began play football.