Section C
16: [C] Only a few species cause troubles to humans.
17: [B] They can cause damages to people’s homes.
18: [A] Deny them access to any food.
19: [D] The change in people’s immune system as they get older.
20: [B] Offer blood samples.
21: [C] Helping improve old people’s health conditions.
22: [D] A group of kids were playing chess after school.
23: [C] Participate in national chess competition.
24: [A] Most of them come from low-income families.
25: [B] Think twice before taking actions.