护理专业最为关注的主体是（）
A.人
B.环境
C.健康
D.疾病
E.护理
参考答案：A
More than two hundred years ago the United States _______ from the British Empire and became an independent country.
A．broke down
B．broke out
C．broke away
D．broke off
当车辆处于极限转向状态时，液压动力转向系统处于（）状态。
A：高压
B：保压
C：泄压
D：增压
