过滤式防毒面具由面罩、环纹管、滤毒罐三部分组成，毒气可通过滤毒罐截留、分解或吸附。
参考答案：对
With Father's Day around the corner, I have taken some money out of the bank ________ presents for
my dad.[ ]
A．buy
B．to buy
C．buying
D．to have bought
正常胎儿血氧含量最高的器官是（）
A.心脏
B.肝脏
C.大脑
D.肺
E.上肢
