By cutting downtrees, we___the natural home of birds and animals. [ ]

What you should do is just ________ the milk until it boils and then turn off the gas.[ ]

English has been very popular because it is the _______ language in many western countries.

t comes to talking about football, his favorite sport, with David, any time will_____ him.

Once a year, people take part in “_______ Lights” activity to help save energy.