If you _______ me with my English, I will appreciate________

________ useful advice it is! It’s very valuable to me.

A new study suggests that the more teenagers watch television,_______ develop depression(抑郁症) as young adults.

Where is Bruce Is he at home — I think he ______ school.

._________ it was to become was a mystery until the dust began to slowly combine into a ball moving around the sun.