Help on these four please

Examine the population chart of niger. based on this chart, niger is in the stage of thompson’s demographic transition. a. balance b. growth c. leveling d. replacement

[ou.01jthe greatest speed with which any physical object moves is 300,000 km/soundsec. which of the following has a speed of 300,000 km/sec? a. light in water b. light in vacuum c. sound in air. d. sound in water

At which boundary does subduction stop occurring, resulting in a mountain range?