1. But for the storm , the ship would have reached its destination on time. = if it wasn't for the storm = 没有了暴风雨 ...
*比起：in case of storm you two take shelter under the roof = 如果下雨的话...
2. The thought came to him that maybe the enemy had left the city. =it occurred to him that maybe... = he suddenly thought that maybe... = 想起
which ； when 这里不能用
3.We should get into the good habit of preparing for the text before class.
固定词组 to get into the habit of ...ing = 习惯做某事
get over = 从(疾病、失望等)中恢复过来,克服(困难等); 从...中恢复过来
get in = 进去
get after = 追上