The ice isn’t ______________ to skate on.
A library with two hundred thousand books _______ to the school last year.
The customs in America are different _______ those in China.
We visited Beijing University _______ the first day of our trip.
_______ 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.