Many _____ in ______ could hear no better than 65-year-old people, for they like pop music.
Science is _____ difficult for some students ____ learn, so many of them don’t like it.
【原创】There are so many kinds of pens in the shop ,I can’t decide __.
—I will go to Dalian with my parents next month. —________
He hardly worries about his English, _______ ?
animals are in danger and there will be space for them if we don’t take any actions.