I. Read and complete. (Đọc và hoàn thành.)
bike/ why/ because/ don’t/ ride
1. ____(1)____ climb the tree!
A: Why shouldn’t I ____(2)____ too fast?
B: Because you may fall off your____(3)____ .
3. A: ____(4)____ shouldn’t I run down the stairs?
B: ____(5)____ you may fall and break your leg.