问题
选择题
Among the 15-year-old children, some studying in university while others are still learning to read and write.
A．should have been
B．would have been
C．can be
D．must be
答案
答案：C
考查情态动词。句意：在十五岁的孩子中间，一些可能在大学学习，然而另一些仍旧在学习读写。选项AB为虚拟语气，选项D为肯定推断，结合语境可知选C。