17.Linda is the most hard-working student in class, ___________?
(1 Point)
is she
does she
isn't she
doesn 't she
18.They had to wear a lot of warm clothes to join this competition, _____________?(1 Point)
didn't they
do they
did they
aren't they
19.Don't touch the present, ___________?(1 Point)
do you
can you
won't you
will you