八年级《物理》(人教版)下册课本第72页的“动手动脑学物理”中的第5题有一幅牵牛花茎的照片(如图1),并以这张照片提出了三个问题:“观察自然界中缠绕植物的茎和攀援植物的卷须,它们的缠绕方向和生长方向有什么关系?这跟螺线管中电流的方向与其北极方向的关系是否相同?对于不同植物,这种关系都一样吗?” The fifth question in the book “Activities and Brain Physics” on page 72 of the eighth grade “Physics” (PEP) is a photograph of the glory of the morning glory (Figure 1), and three photos are presented in this photograph. Question: “Observe the nature of the winding stems of plants and the tendrils of climbing plants. What is the relationship between their winding direction and the direction of growth? Is this the same as the direction of the current in the solenoid and its north pole? For different plants, this kind of Is the relationship the same?”