The second-simplest standing wave you can have on a string with two fixed ends has 3 nodes -- one at each end, and one in the middle -- plus 2 antinodes in between the nodes.

具有两个固定端的弦上第二简单的驻波有 3 个节点——每端一个，中间一个——加上节点之间的 2 个波腹。