虚函数必须是类的______。
参考答案:成员函数
何谓典型相模式,作为典型相模式应具有哪四种作用?并列举3个目前已比较公认的沉积相模式(相层序)。
She wandered to the other side of the hall and ____ another painting on the wall.
A.came across
B.came up with
C.came out
D.came along