His sister left home in 1998,and__________ since.
If you ____ do as I tell you , you ____ go to the party .
Li Ling was a diligent boy . He ____ go to school though it was raining hard .
The work ____ be finished in such a short time .
— ____ he open the door ? — Yes , please .
— Do you have to take care of your mother at home ? — Yes , I ____ .