You can improve your English_______practicing more.

This is Jim’s room. It’s a nice room. Some pictures are on the wall (墙). There’s a desk and a chair in his room. There is a sofa and a bookcase, too. The desk is between (在……之间) the bed and the bookcase. His backpack and pencil case are on the desk. His pencils, pen and ruler are in the pencil case. His sofa is near the desk. His baseball is under the bed.

气体从外界进入人体血液内最合理的路线是（　　）