以下哪一种特点仅属于碘标记放射免疫分析技术（）

A.灵敏度高、特异性强

B.测定重复性好、标本及试剂用量少

C.操作简便、易于标准化

D.测量信号不易被屏蔽

E.安全、不污染环境

Would you like to sleep with the windows          or          ?[ ]

A. open, close

B. opened; closed

C. open; closed

D. opening; closing