You must be sure ________ the reason of the accident．
These days my grandparents come to visit us from the countryside．Look, my grandmother ________(clean)the floor．My grandfather ________(read)the newspaper．
We are going to visit the Great Wall next month．Would you like ________(go)with us?
Bob is not talking．He ________ her．
[ ]
A．
listen to
B．
is listening
C．
is listening to
D．
listen to
－Where is your father?
－He ________ still ________ in bed．He doesn't need to go to work today．
