351. The lecture which lasted about three hours was so tedious that the audience couldn't help yawning.
译文
持续了三个小时的讲座太枯燥了，听众都忍不住打呵欠了。点睛
couldn't help doing sth.相当于can't help doing sth.，意为“不能控制自己（情不自禁地）去做某事”。如：I can't help refusing to accept his invitation. 我不禁拒绝了他的邀请。
