一、写出下列单词的过去式。1.help_ 2.run_ 3.crash_ 4.fall_ 5.pick_ 6.work_ 7.cook_ 8.stop_9.sit_ e_ 11.has_ 12.wait_二、用括号里面单词的正确形式填空。1. We all _(go) to play in that park yesterday.2. Look, the children _(swim) in the lake now.3. They didnt _ (run) in the playground last week.4. The man usually _ (study) English under a bi