There are some birds_________ happily in the trees.A. sing B. are singing C. singing
—Bob, it’s getting cold outside. ______ take a jacket —All right, Mum.
Some people won’t realize the importance of their health ______ they have lost it.
—Which do you prefer, tea or coffee? —I don’t care. ______ is fine.
Excuse me, I lost my way. Will you please tell me ______?
Paul isn’t as ______ as Sandy. He often makes mistakes in his homework.