Les modaux

1 - They ... at least two hours ago.
should leave
must have left
ought to leave
can leave
2 - I met them this morning, so they ... be away on holiday.
might not
can't
oughtn't to
are not to
3 - We'd better keep our promise, ...
don't we ?
didn't we ?
wouldn't we ?
hadn't we ?
4 - ... stay at home, wouldn't you ?
You'd rather
You'd better not
You shouldn't
You'd needn't
5 - You ... find Linda in the garden, but I doubt it.
can
should
might
must