单项选择题A.That more work is necessary for those facts.B.That animals are helpless to healthy people.C.That animals can also become friends of humans.D.That they had a very successful discovery.
单项选择题A.Average tuition costs increased by 9 percent.B.Average tuition costs increased by 15 percent.C.Average tuition costs increased by 90 percentD.Average tuition costs increased by 150 percent.