English Grammer

Most of your answers are correct except A2 which should be "Miss Lee didn't finish the work on time."

I think the A2 was mistake was accidental. 囧 Also, the last question should probably be 'where did they catch ...'?

To answer your question (轉成過去式否定句，動詞不變，是否過去式否定句全部都要用didn't，會有其它變化嗎？), not all. The whole deal with don't and didn't is, believe it or not, unique to English and Celtic languages IIRC. In English, when there is no auxiliary verb present, we add the auxiliary 'do' in negative and interrogative sentences; however, if there's already an auxiliary verb, there's no need to add 'do'.

(Auxiliary verbs are verbs that are followed by lexical verbs)

Oh, I can see you! --> Oh, I can't see you! (NOT Oh, I don't can see you!)
Oh, I could see you! --> Oh, I couldn't see you! (NOT Oh, I didn't can see you!)

I will try. --> I will not try. (NOT I don't will try.)

[Can/could, may/might, shall/should, will/would, ought to, etc., are modal auxiliaries]

I did want to eat. --> I didn't want to eat (NOT I didn't do want to eat)

I have smiled. --> I haven't smiled. (NOT I didn't have smiled.)

I wanted to eat --> I didn't want to eat (NOT I wanted not to eat in Modern English, although it was used in the past)

[Emphatic do, the perfect auxiliary have, etc., are also auxiliary verbs]

THX...........