Give a reason account on the impact of tourism on man and the environment

What does the word submerged mean in the following sentence? after it rained for three days in a row, the streets were completely submerged.

The yellow river is also known as the huang he river? true or false

Which of the following is not a pillar of the nuclear proliferation treaty? nonproliferation reduction of nuclear weapons by 85-90% right to peacefully use nuclear power disarmament