重点讲解:
1. be known as 称为;叫做;
The disease is more commonly known as Mad Cow Disease.
这种疾病更通俗的名称是疯牛病。
2. care for 照料;照顾;护理;
She moved back home to care for her elderly parents.
她搬回家住,好照料年迈的双亲。
3. go down (价格、水平或数量)下降,下跌;
Crime has gone down 70 percent.
犯罪率下降了70%。
4. serve as 担任(职务);
He served as a captain in the army.
他曾是一名陆军上尉。











