I.
2.Elephants are large animals.
3.Your heart beats faster when you exercise.
4.Healthy hearts need regular exercise.
5.Every child in the class knows the alphabet.
6.Some of the magazines at the dentist's office are two years old.
7.A number of the students in my class are from Mexico.
8.One of my favorite subjects in school is algebra.
9.There are many different kinds of insects in the world.
10.Writing compositions is difficult for me.
11.The United States has a population of mora than 250 million.
12.Most of the people in my factory division like and get along with one another, but a few of the workers don't fit in with the rest of us very well.
II.
1.is
2.are
3.barks
4.bark
5.is
6.are
7.are
8.are
9.is
10.are
11.are
12.is
13.are
14.is
15.are
III.
1.is
2.are
3.is
4.are
5.has
6.have
7.were
8.was
9.was
10.are
11.is
12.have
13.has
14.have
16.is
17.are
18.is
19.are
chúc bạn học tốt!!!!
