这些名词均含有“枝”之意。
branch : 普通用词，泛指树木比bough小一些的大枝或小枝，也可用于引申意义。
- bare/leafy/flowering branches
光秃秃／叶子茂密／开满花的树枝 - The fruit on the lower branches was protected from the sun.
下边树枝上的果子见不到阳光。 - Watch out for overhanging branches.
小心下垂的树枝。
limb : 多指主枝或大枝。
- An 18-year-old student at California State University died yesterday when she was struck by a falling limb from a large oak tree.
昨天，一位18岁的加州州立大学的学生被一棵大橡树上落下的粗树枝打中身亡。
bough : 指主枝或粗大强壮的枝。
- I rested my fishing rod against a pine bough.
我把钓鱼竿靠在一棵松树的大树枝上。
shoot : 指植物或灌木刚长出的新枝、嫩枝或嫩芽。
- Two weeks after we'd planted the seeds, little green shoots started to appear.
我们撒下种子两周后，绿色的小苗开始钻出来。 - The first green shoots (= hopeful signs) of economic recovery have started to appear.
经济复苏的迹象已开始显现。
