At school our teachers do all they can______ us with our les

At school our teachers do all they can______ us with our lessons.
A、help
B、helping
C、to help
D、helped
Where"s Miss li,do you know?
Well,it"s hard to say.But I heard her ______just now.
A、was singing
B、singing
C、had singed
D、singed
I often see my teacher,_____books in her office.
A、reads
B、to read
C、read
D、is reading
I spend some time______TV news every day.
A、on watch
B、in watching
C、to watch
D、learned
答案分别是C B C B