doing morning exercises --------(be) good for our health
问题描述：
doing morning exercises --------(be) good for our health
答
doing morning exercises ---is-----(be) good for our health
做早操有益于我们的健康。
doing morning exercies是主语，做早操，晨练的意思，是单数
答
is
答
is
doing morning exercies是主语,晨练的意思,是单数.