She tried hard to keep calm in face of the students, but the sweat on her forehead _____ her ____.

will take part in the Summer Olympic in Rio de Janeiro, Brazil–10500 athletes from 206 countries around the world are preparing to compete there.

Evidence gained from observation and experiment is often used to _______ a scientific theory.

There ____ a heavy rain in Beijing tomorrow .

It will be too cold for us ______ to the park.