重点讲解：
1. be close to 近的；接近的；
The total was close to 20% of the workforce.
总数接近劳动力的20%。
2. stand at 处于(某一水平)；
Interest rates stand at 3%.
利率为3%。
3. call on sb. to do sth. 要求；呼吁；号召；
The United Nations Secretary General called on all parties to show moderation.
联合国秘书长呼吁各方要表现出克制。
4. step down 辞职；下台；让位；
He stepped down last month because of illness.
他上月因病辞去了职务。