I’m worried about my English.—_____ harder, _____you will catch up with your classmates.

The lake is calm and clear, and one of the things that _____in the water is the famous tower.

I really appreciate that your help is of great .

alking about doing exercise, you should choose an activity that you enjoy and _____ that you will stick with.

It was his studying in No.2 High School of Baoding for three years ____ laid the foundation of his successful career.[ ]