I think convergent is the word bcz it means that two plates that hit each other and formed the appalachain mountains hope its right.
Explanation:
<h3>The frequency is = 1/t = w/2π of the motion per unit time. It is measured in Hertz. (1hz = 1m/s.) </h3>
D. blue and white porcelain
Niger and Congo are two rivers after which countries are named (actually in both cases two countries each) - and those are African countries, so they must be in Africa.
Zambezi is a river in Angola and Namibia.
Tigris is a River in Mesopotamia, in Asia - so that's the correct answer!