III.
1.C (Ever since baseball was invented, it has been the national sport of America)
2.C (Minor League baseball is for adults who play professionally, but are not good enough for the Major Leagues)
3.B (Every year, the Major League Major Leagues hold the World Series)
4.D (Usually, the President of the United States throws the first ball)
IV.
1.We began learning English 5 years ago.
2.Although it was cold, we went swimming.
3.I'm younger than Hoa
4.Do you feel or hungry?
5.Alison is the tallest student in the class.
6.There are thirty days in April, June, September and November.