She won't open the door, unless she knows who it isIf you painted the walls white, the room would be much brighterIf your brother had driven more carefully, the accident wouldn't have happenedI shouldn't have believed it if I hadn't seen it with my own eyes Ice turns to water if you heat itIf he reads in bad light, he will ruin his eyes I could tell you what this means if I knew Chinese If she had worn her raincoat, she wouldn't have got wet