i used to be afraid of the dark.为什么dark前要加the?

i used to be afraid of the dark.为什么dark前要加the? 英语i used to be afraid of the dark “I used to be afraid of the dark. I used to be afraid of the dark. I used to be afraid of the dark used to be+动原 句子 例：I used be afraid of the dark. i used to be afraid of the dark and went to with the bed roo (1)dark,she,be,to,afraid,used,of,the (2)choose,to,I,which,bu I used to be afraid of the dark它的同义句是 I used to be afraid of the dark.这句话的句子成分怎么分? 如何上好unit 4 i used to be afraid of the dark Mum used to be afraid of the dark.So _________ I.A.did B.do