________cleaning the yard and making up the beds for the  old,  we also read newspapers for them

and had chats with them.   [ ]

A. Except for  

B. Rather than

C. Apart from  

D. Instead of

先将一密闭透明的实验装置（图甲）于晴天的晚上22时置于室外，并进行24小时的气体分析测定，得出气体含量变化曲线（图乙），该气体是

A．氧气

B．二氧化碳

C．水蒸气

D．氮气