1.
因为forget
to
do表示忘记去做,
而forget
doing
表示”做了,但忘记了“,在这里只能是版forget
to
do2.
prefer
to
do,
prefer
doing
to
doing,
prefer
to
do
rather
than
do.
rather
than
do省去to是固定用法。权3.
因为主语是secretary,
用preparing表示伴随,是secretary做的,如果要用prepared的话,前面要加and,因为一个主语可以做多个动作,但最后一个动作要用and4.
因为人+
be
lost
in
thought是固定搭配,所以要用lost.
过去分词表示状态。