If they are not careful,they ________________ a window.

题目

If they are not careful,they ________________ a window.
If you boil water,the water ________________ into steam.

答案

If they are not careful,they __will break___ a window.
If you boil water,the water __will turn / turns__ into steam.一般if用现在加将来；由於是事实,应该也可以用现在加现在