用所给动词的适当形式填空。 1. I believe your dream (come) true soon. 2. We should do everything we can (solve) the problem. 3. Unluckily, he (break) down from the hard work. 4. Over the past years, great changes (take) place in my hometown. 5. The old walls must (pull) down as soon as possible. 6. She couldn't help (cry ) when she heard the bad news.