用括号内所给动词的正确形式填空。
1. He__________(drink)a cup of coffee and began to speak.
2. Look! The kids__________(swim) in the river.
3. Don't go across the street until the traffic lights _________(turn) green.
4. I hear she__________ (be) twenty years old next year.
5. He_________(write) to me as soon as he arrives in Hong Kong.
