下面的描述中，（ ）不能正确定义一个名为 Student 的结构体以及一个包含20个元素的结构数组。
1 struct Student {
2 string name;
3 int age;
4 float score;
5 };
6 struct Student students[20];
1 struct Student {
2 string name;
3 int age;
4 float score;
5 };
6 Student students[20];
1 struct Student {
2 string name;
3 int age;
4 float score;
5 };
6 Student* students = new Student[20];
1 struct Student {
2 string name;
3 int age;
4 float score;
5 };
6 Student students = new Student[20];