Hoàn thành bài tập sau

61.he uses milk for making butter and cheese
62.she makes progress every day in the world of science
63.the author will write this novel in june
64.nobody will solve this hard problem
65.her mother will take her to hospital next weel 
66.someone will clean the room
67.they had to cut down that tree
68.someone should tell sally what happened
69.they're going to build a new hospital
70.we can solve the problem