连续发生的一系列生理活动可用流程图来表示,以下流程图中不正确的是( )
A:氧气进入人体的过程:鼻腔→咽→喉→气管→支气管→肺泡→肺泡周围毛细血管
B:肺循环:右心室→肺动脉→肺部毛细血管网→肺静脉→左心房
C:反射弧结构:感受器→传入神经→神经中枢→传出神经→效应器
D:尿素分子排出体外的主要过程:血液→肾小球→肾小管→肾小囊→尿液
已知锐角A,B满足2tanA=tanA+B,则tanB的最大值为( )
用于显微镜观察的实验材料必须是( )
先阅读短文,然后用下面方框中所给的单词或短语填空,使全文在逻辑上正确。(提示:选项中有一个是多余的。)
I’d like to tell you a story about my best friend Jane. Last week in school we had a big fight, and she didn’t____ me. It all started when she asked me if she could copy my homework. I asked her why she wanted to do that, and she said that she had forgotten to do hers. I said I didn’t think it was a good idea. I said it would start a bad____ and she should do her own work. She got really____ at me and said she didn’t want to be my best friend anymore. I said that was OK and that I was sure she would ____ it. And she did. Yesterday she told me she was ____. She said it was much better if she did her own work.