Astronomers and scientists think that a black hole is a region of space ______ which matter has fallen and _______ which nothing can escape.
What a pity. The car ran out of sight before I could ______ its number.
----Volunteering is becoming ______ popular in China. ---- Yeah. People are now aware that helping others is helping themselves.
Thanks to their hard work, the new bridge has been finished ________.
The second Sunday of May is Mother’s Day and a time to be to our mothers.
Some parents are just too protective. They want to ______ their kids from every kind of danger, real or imagined.