—Do you often ______ your sister?    
—Yes, she often writes to me.   

Bob enjoy playing computer games. He         all his free time on it.

I will help my mother          the pet dog while she is abroad.

—All the oil in the world will be _______ some day.       
—Yeah. What shall we use for power at that time?     

My best friend Alex failed in the math competition. I'd like to _________.

Spring is coming, all the flowers start to__________.

Change the sentences.
1. It took the Clarks two hours to clean their kitchen last Saturday.
    The Clarks __________ two hours __________ their house last Saturday.
2. When I read love stories, I feel moved.
    Reading love stories often __________ me __________.
3. When does the train leave? I want to know. (Put the two sentences together.)
    I want to know __________ the train __________.

He likes music very much and I often see him _________ music.     

Don't __________ the window.Listen to me carefully.

The plane will ______ in twenty minutes. You'd better hurry up.