单词与短语：
1. commitment n. 承诺，保证
eg. We made a commitment to keep working together...
我们承诺继续合作。
eg. They made a commitment to peace.
他们承诺要维护和平。
2. ungraded adj. 劣质的，没有分等级的
eg. You can revert any ungraded assignment back to draft status.
您可以把任何未打分的作业恢复成草稿的状态。
eg. The vegetables I just bought are all ungraded goods.
我新买进的蔬菜都是统货。
3. idiot n. 笨蛋，白痴
eg. I knew I'd been an idiot to stay there...
我知道我呆在这里很蠢。
eg. You're an idiot!
你是个白痴！
4. collapse v. 倒塌，瓦解
eg. Most of the deaths were caused by landslides and collapsing buildings.
大部分死亡是由山体滑坡和建筑倒塌造成的。
eg. His business empire collapsed under a massive burden of debt...
他的商业帝国无力承担沉重的债务负担而垮掉了。
5. be grounded 关禁闭
eg. He is always grounded by his parents for a week.
他常常被父母禁足一周。
eg. That's why you are grounded for two months!
这就是为什么你被禁足两个月!