logs experienced rapid growth in 2011 in China,with the number of microblog operators, users and visitors _____ several times

Why are you smiling at me? — You look _______ in that hat.[ ]

It is usually warm in Autumn here. But it _____ be freezing sometimes.

The present question is ____ many students consider it impossible ____ is really possible if effort is made.

g his friend calling him , out __________ .