关于激素的说法,正确的是( )
如图所示,物体在恒力F作用下处于静止,则下面对物体受力情况的分析正确的是( )
A. Oh, I'm sorry.
B. It's green. We can go.
C. They're waiting.
D. I'm going to work.
E. Thank you.
根据如图1所示实验装置图,回答有关问题.