Tom hid himself behind the door, _______ he rushed out to scare his mother.

It was not until I had read your e-mail _____ I understood what you had done for the students.

predicted the disaster, he _______ his girl friend to the 2015 New Year’s celebration at the Bund, Shanghai.

The boy isn’t to dress himself.

What __________ your father __________—He’s generous and polite.