1. am/is –was 动词“是” 2. are—were 动词“是” 3. become—became 变为,变成 4. begin—began 开始 5. buy—bought 买 6. bring—brought 拿来,带来 7. beat—beat 敲打,搅拌 8. blow—blew 吹,吹动 9. break—broke 打破,打碎,折断 10. build—built 建筑,建造