阅读理解。

     This is a picture of Mr. Li's family. The man in the middle is Mr. Li. The woman is Mr. Li's wife. They have two sons. The child behind Mr. Li is Li Lei. He's thirteen. The other in front of Mrs. Li is Li Ming. He is eleven. Li Lei and Li Ming are in the same school, but not in the same grade. Li Lei is in Grade Two. Li Ming is in Grade One. They are good students.

1. There are _______ people in the picture.

A. three

B. four

C. five

D. six

2. LiLei and Li Ming ______ in the same grade.

A. is

B. isn't

C. are

D. aren't

3. Mr. and Mrs. Li have _______.

A. one boy, one girl

B. two children

C. two girls

D. one boy

4. Li Ming is ________ brother.

A. Mr. Li's B. Mrs. Li's

C. Li Lei's

D. we don't know.

5. How old are Li Lei and Li Ming? They're _____.

A. eleven and thirteen

B. eleven and twelve

C. twelve and eleven

D. thirteen and eleven

对经过筛选后的数据清单进行二次筛选时，之前的筛选结果仍然保留.