Since my grades in the first semester were not good, I have to work harder in the second semester.

Sales for this period have significantly increased compared to the previous period.

Recently, the population in this area has been increasing rapidly.

The population is increasing rapidly.

The stock price dropped significantly today.

This year's sales have increased significantly.

This year's sales increased by 20% compared to last year.

This year's sales increased by 20% compared to last year.

He decided to participate in the contest.

He compared his grades with his friend's grades.