He coughed day and night．His wife asked him smoking．

Scientists estimate that plants and animals lived _____ 3.5 billion years ago[ ]

_________ not for all the cars and passers-by with cameras, you _________ think you have magically traveled back to the 14 century.

I’ll give you my friend’s home address______ I can be reached most evenings[ ]

Through so much trouble，he learned ________ everyone needed friendship and ________self confidence is important