请帮忙找一下下面英语句子中的错误

题目

请帮忙找一下下面英语句子中的错误
单句改错：
1.Do not take it too seriously;I just do it for amusements.
2.What a great fun to play football on such a day!
3.All the glasses that were on the table were seen fall off onto the floor.
4.China is the first country to study the science of the agriculture.

答案

1.amusements--amusement
2.on--in
3.fall--falling
4.去掉agriculture前的the