【正确答案】 B

【答案解析】[听力原文]
   Health officials in Brazil have declared a state of emergency in several states. They are also warning women not to get pregnant. These extreme actions are the result of a recent rise in birth defects. About 2,400 babies in Brazil were born recently with extremely small heads. The babies have a condition called microcephaly. Microcephaly causes severe brain damage. To date, 29 of these babies have died. The number of microcephaly cases in Brazil is about 10 times higher than what the country usually sees in a year. The U.S. Centers for Disease Control (the CDC) explains on its website that there are many causes of microcephaly. And the World Health Organization WHO said in a statement that the cause of the microcephaly outbreak in Brazil had yet to be determined. However, the CDC says the link between a virus infection and microcephaly is being investigated. The virus is called Zika. Zika is spread by mosquitoes. Some babies in Brazil with microcephaly have tested positive for the Zika virus while others have tested negative.
   How many babies born in Brazil recently are with extremely small heads?
数字听力题。新闻中画线句提到在巴西，有将近2,400名新生儿有极小的脑袋，即小头畸形胎儿。故答案为B。