1g血红蛋白可结合的氧量为
A．0.34～0.39mlB．1.34～1.39mlC．1.39～2.34mlD．2.34～2.39ml
参考答案：B
单项选择。
Lily and Lucy are twins. They ______. [ ]
A．look like
B．look like the same
C．look the same
D．looks like
血液可以看作是人体细胞与外界环境进行物质交换的媒介。 ( )
