Question

【题目】When H7N9 bird flu first appeared, people didn't know doctors could cure it.

A. if B. that C. what

Answer 1

【答案】A

【解析】句意：当H7N9禽流感首次出现时，人们不知道医生是否能治愈它。if是否；that那个；what什么。根据句意，人们不确定，医生是否能治愈它，故选A。