基本解释低树层英汉例句双语例句In shrub-tree stage , the species diversity in tree layer was lower than that of shrub layer .灌乔林过渡阶段群落乔木层物种多样性指数低，而灌木层多样性指数高。lower tree layer更多例句词组短语短语lower punch tree layer 低树层lower tree layer更多词组