Questions 19 ～ 22 are based on the following conversation.

What job does Liz Pennington apply for

What is the substance in cigarettes that causes cancerA...

单项选择题What is the substance in cigarettes that causes cancer

How many animal diseases are mentioned in the interview...

单项选择题How many animal diseases are mentioned in the interview

What disease was reported in Yemen and Saudi ArabiaA．Sw...

单项选择题What disease was reported in Yemen and Saudi Arabia