He said that light ______much faster than sound.
_______ is necessary for us _______ our own dreams.
--Who is the man over there? Is it Mr. Li ?--No, it _______ be him. Mr. Li is much taller.
What will the weather _______?
_______the population of China?_______over 1,300,000,000.
Do you know the man _______Tom is a bus driver?Yes, he is my friend.