5. Which of the following best describes how a frozen river can cause a flood.
a. The ice in the river melts too quickly and causes a flood.
b. The ice in the river cracks causing the water to overflow.
c. The ice in the river cracks into pieces
that eventually create a dam causing the water to overflow.
d. The water behind the ice dam collects and when the dam breaks, it causes flooding upstream.
6. How far can dam water travel when it is unleashed from a broken dam?
a. less than 10 kilometres
b. tens of kilometres
c. thousands of kilometres
d. tens of thousands of kilometres downstream