一般情况下，年龄超过（）岁，机体新陈代谢即逐渐减退，各器官的机能也相应降低。
A、30~35
B、35~40
C、40~45
D、45~50
参考答案：B
_______makes her different from other students is that she likes being alone.
A．Which
B．That
C．What
D．Whatever
简述燃气锅炉运行操作时注意事项。
