小心走楼梯，扶着栏杆。

Be careful on the ___stairs; hold onto the ___handrail.

上下楼梯时请扶好扶手。

Please hold the ___handrail when going up or down the stairs.

上下楼梯时请扶好扶手，以确保安全。

Please hold the ___handrail when going up or down the stairs for safety.