16: What is the highest of the following levels of the atmosphere?
18: Which of these mammals is the largest animal in the world?
19: Which of the following do all mammals have?
21: Certain types of cancer are genetic.
22: Ethnicity is a factor in the development of skin cancer.
23: HPV is a virus that has been linked to cause cancer.
24: Men cannot develop breast cancer.
25: Cancer is a group of over 500 diseases.
更新1:
ones without a question mark want to know if it is true or false.
