Which is the big country

Which of the following lakes is not found in africa?

There are 4 red balls, 6 white balls, and 3 green balls in a bag. if one ball is drawn from the bag at random, what is the probability that it is not white?

Some gamma ray bursts are hypothesized to come from mergers of neutron stars or black holes. if this hypothesis is correct, what else should we in principle be able to detect from such mergers? a. gravitiational waves b. x-ray bursts c. significant disruption of gas thousands of light-years away in the surrounding galaxy d. an "afterglow" of bright visible light, lasting for weeks