simple pinnate compound leaf

• 单出羽状复叶

simple pinnate compound leaf的用法和样例：

例句

1. The model hypothesizes, for example, that a simple tubular feather preceded the evolution of barbs because barbs are created by the differentiation of the tube into barb ridges.
   比如，我们的模型假设，简单的管状羽毛先于羽枝的演化，因为羽枝是由管子分化出羽枝脊才产生的。