Some of my friends are interested in science,but none of them can tell A when UFOs will appear next time B why do horses know the wayC where was this kind of plant found D how do elephants communicate
It’s very late now. It’s time ______ goodbye.
— Anna, have you ______ seen China’s Got Talent (达人秀)? — Of course. I ______ it last weekend.
The idea ________ good. We can try it.
--- It’s hot today. Why don’t we go swimming? ----_________.
---- Has John come ________? ----Yes. He has _________ been here for 10 minutes.