did you see a dog___(lie) on the road with your own eyes?they have never___(ride) a motorbike beforeit's 12 years since hongkong ___(come)back to china
问题描述：
did you see a dog___(lie) on the road with your own eyes?
they have never___(ride) a motorbike before
it's 12 years since hongkong ___(come)back to china
答
lying see sb doing sth
ridden 现在完成时 have +过去分词
came 从句一般过去时