成年人的血量约占体重的( )
A:1~2%
B:10~15%
C:7~8%
D:18~20%
2008年5月8日北京奥运火炬成功登顶珠穆朗玛峰。为解决登顶人员的呼吸困难,应携带的物质是()
-I didn't hear you come just now.
-That's good. We tried __________ any noise, for you were sleeping.