--What's wrong with your uncle?--- We're sure____ something is wrong with him, but we doubt_____ the disease can kill him.
---My mother is ill. ----_______ .
Mr Zhang is one of ____in our school.
– Are there cats in the classroom? –No, there aren’t .
The boy didn't run _______to catch the bus.
It is ____ useful book. ____ book is on her desk.