The boy ran so fast that I couldn't catch him.变为too...to.句型

The boy ran so fast that I couldn't catch him.
变为too...to.句型

the boy ran too fast for me to catch him

The boy ran too fast to catch him~

两个角色回答不错！还可更精确点,加上大写和句点：
The boy ran too fast for me to catch him.