What _________unusual school trip we had! I will never forget it．（　　）

A．aB．anC．theD．/

You'd better not hang out after school _______telling your parents． They may worry about you．（　　）

A．byB．withC．withoutD．after

Li Lei didn't play computer games last weekend．__________，he worked as a volunteer in an old people's home． （　　）

A．InsteadB．CertainlyC．ThoughD．Gradually

Please remember to _________the electricity and water before you leave the laboratory．（　　）

A．take offB．shut offC．go offD．put off

Is this hat_______________？

No， the red one is_________．（　　）

A．Lucy's； herB．Lucy； her

C．Lucy's； hersD．Lucy； hers