One day, Tom found a little bird in the garden. The bird was weak. Tom took it to his room and looked after it well. Soon the bird got better. Tom bought a cage and kept the bird in it. But when the bird was in the cage, it didn't eat anything.
Tom felt worried that the bird would die if it didn't eat food all the time. Then he thought the bird must be missing its family and friends. It wanted to fly in the sky. So Tom took the cage to the window and opened the cage. The bird flew happily into the sky.
The next morning, when Tom woke up, he heard birds singing outside the window. “The bird must be with its family and singing to me,” he thought.
【高分句型】
1. Tom felt worried that the bird would die if it didn't eat food all the time. （汤姆担心这只鸟如果一直不吃东西会死掉。）
if 引导条件状语从句；
be+形容词+that 引导宾语从句。
2. Then he thought the bird must be missing its family and friends.（然后他想这只鸟一定是想念它的家人和朋友了。）
must be doing 一定在做... 肯定推测；
3.when Tom woke up, he heard birds singing outside the window. （当汤姆醒来时，他听到窗外鸟儿在唱歌。）
when 引导时间状语从句
