A、6. B、16. C、60 BThe Amazon，亚马逊河。新闻中提到由于亚马逊河水位下降导致船运困难，在上周五的一次船运事故中16人丧生。

The Amazon is a lifeline for everyone in the river basin, from businessmen in the big city of Manaus to indigenous tribes in remote settlements. When water levels fall, the biggest effect is on transport-ferries and barges are the only way of moving goods and people around an area that spans about half the South American continent. In the last few weeks, the river and its tributaries have become increasingly difficult to navigate, and vital supplies of food, medicine and fuel are now struggling to get through. In an example of the risks, sixteen people were killed last Friday in a ferry accident which the captain blamed on difficult river conditions.
Question: How many people were killed last Friday in the ferry accident?