Humans have four blood types(血型). They are blood type A, B, O and AB.
The table below shows all kinds of possible blood types of parents and their children. Children’s blood types are shown in grey squares.
| MOTHER FATHER | A | B | O | AB |
| A | A, O | A, B, O, AB | A, O | A, B, AB |
| B | A, B, O, AB | B, O | B, O | A, B, AB |
| O | A, O | B, O | O | A, B |
| AB | A, B, AB | A, B, AB | A, B | A, B, AB |
( ) 56. If both parents are blood type O, then their children must be ________.
A. blood type A B. blood type B
C. blood type AB D. blood type O
( ) 57. If a father is blood type A and a mother is blood type B, then their children’s blood types may be __________.
A. any blood type B. blood type A and B
C. blood type AB and O D. blood type A, B and AB
( ) 58. If both parents are blood type AB, then their children can NOT be ____.
A. blood type A B. blood type AB
C. blood type O D. blood type B
( )59. If both children of the same parents are blood type A, B, O and AB, then their parents should be __________.
A. blood type A and B B. blood type A and AB
C. blood type B and AB D. blood type AB and AB
( ) 60. If one parent is blood type AB, and his or her nine children only get blood type A and B, then the other parent’ s blood type is likely to be(可能)__________.
A. blood type A B. blood type B C. blood type AB D. blood type O