If H2 burn in O2, we can get _____.
My brother spendstime in front of the computer.
The girl is afraid of dark, so she always sleeps with the light.
---How is everything going in the school, my boy? ---_______.
He used to _______ in a village, but now he has been used to _______ in the big city.
_______ he exercises every day, _______ he is very healthy.