密密层层 严严实实 葱葱茏茏
树木长得____，____的枝叶把森林封得____，挡住了人们的视线。
I love pandas because they are so cute and _______.
It is generally believed that mutual understanding ______ a happy marriage and life.
在无外伤的情况下，当尿中同时出现红细胞和蛋白质时，肾脏发生病变的部位是（ ）
