關於「過去式」與「過去完成式」「過去進行式」????????

Then is somehow redundant, since <and> has already indicated progression.


Yes, 7am is the exact time.
But there is no indication of its immediate occurrence, by which the present perfect tense is suggested.

Thus, for simplicity, just use the past tense.

1.
Kate turned on the tv and then sat down to watch her favourite programme.
(1.wrong word
2.that kate do the first thing first and then do another thing so it is the same)

we waited until Ann came and then we set off .
(and that sentences...:
U know that 'until' that word is from [1]---->[2a->>b]
like that eg:
we stopped until I came,then we go out the bus. )
3.i met Tom at 7 a.m. at the bus stop.
= =
that is a time,but not U say...
that is the same of the time table...