单项选择题


Questions 23~25 are based on the following news from the BBC or the VOA. At the end of the news item, you will be given 15 seconds to answer the three questions. Now listen to the news.
The WHO has warned that ______.

A.the skies over Mozambique have been too busy
B.malaria has risen sharply
C.medical services have not been available
D.medical staff is not enough