—I can never forget the days       we spent together in the summer camp.—Well, especially the day       it suddenly began to rain in the middle of the night.

The college student lost his life trying to save the drowning child, ________ he will always be remembered.

That is not the way ______I do it. 

Mobile phone users have developed a series of symbols, such as ^_^ and └(^o^)┘， to show      they feel.

 After retirement, learning a musical instrument may be harder than ______ when you were a kid.