单选题 He______late into the night, but now he goes to bed early due to health reasons.

【正确答案】 A

【答案解析】句意:以前他经常加班到深夜,但现在因为身体原因,他早早就睡了。used to do sth. 意为“过去常常做某事”,be used to doing sth.意为“习惯做某事”,故选 A。