Group B verbs have different forms for the Simple Past and the Past Participle. Type the Simple Past on the left, and the Past Participle on the right.
blow
bl_w
blow_
grow
gr_w
grow_
know
kn_w
know_
throw
thr_w
throw_
fly
fl_w
flow_
draw
dr_w
draw_
see
s__
see_
If you want, after finishing the exercise, you can listen to the pronunciation of these verbs: