纸层析法分离叶绿体色素时，滤纸条下端第二条的色素名称和颜色分别是 [ ]

A．叶绿素a、蓝绿色

B．叶绿素b、黄绿色

C．胡萝卜素、橙黄色

D．叶黄素、黄色

My best friend is good___ swimming, but I do well ________running.

A．at; in

B．in ; at

C．at; at

D．in; in