It was about 600 years ago _______ thefirst clock with a face and an hour hand was made.

natural parks are important forpreserving animals, which would ________ risk dying out

The performer was waving his stick inthe street and it ___ missed the child standing nearby.

My most devoted friend, ProfessorYang, _______ often go hiking when he lived in the mountain that was coveredwith forest.

I have no time left now. Can wediscuss the matter ________ supper