Can you solve the river crossing riddle? - Lisa Winer

Important Vocabulary Words From The Video


The grasslands are a type of biotic community that is found in dry areas. They are dominated by grasses, but they also include other types of plants.

  • The grasslands are a type of biotic community that is found in dry areas.
  • The grasslands are a type of biotic community that is found in dry areas.

A wildfire is a large fire that is started by a small fire. A wildfire can quickly become a very large and dangerous fire.

  • The wildfire is quickly spreading and is now threatening many homes.
  • The wildfire started by the small fire is now a large and dangerous fire.

The wildebeest is a large animal that is often seen on the African plains. It is a type of antelope, and it is one of the most common animals in the area.

  • There were so many wildebeest in the park that it was difficult to walk through the park.
  • The wildebeest are a endangered species, and they are in danger of extinction.

To be infested is to be full of something unpleasant. The word can be used to describe anything from a room to a whole country.

  • The house was infested with spiders, and it was very difficult to live in.
  • The country is infested with corruption, and it's very difficult to live there.

To outnumber somebody is to have more people than they do. If there are 10 people in a room, and 20 people want to enter, the 20 people will outnumber the 10 people.

  • The stadium was outnumbering the number of people that the protesters wanted to see.
  • The company outnumbers the number of customers that it wants to serve.

The instincts are the basic impulses that we have as humans. These impulses include things like hunger, thirst, and the need to survive.

  • Our instincts tell us to eat.
  • Our instincts tell us to run away.

When there are more people against you than there are people for you, it's called being outnumbered. This can be a really dangerous situation, because you don't have a lot of support.

  • The army was outnumbered by the soldiers of the king's army.
  • The company was outnumbered by the protesters, and they were eventually defeated.

To reverse something is to turn it around, to go in the opposite direction. When you reverse the polarity of a battery, you change the direction of the electricity.

  • When she turned the key in the ignition, the car started and the lights turned off.
  • Reversing the charges on the battery reversed the polarity.

When someone is unharmed, they are not injured in any way. They might be unharmed by the accident, or they might be unharmed by the other person's words.

  • He was unharmed by the accident, and he was able to help the other drivers.
  • The unharmed soldiers were able to retreat and protect themselves.