describe difficulty to be faced due to difference on measurement unit in different countries ? what effort are made to bring uniformity?

Why does karst topography exist in some geographic location? a. few climates have enough oxygen b. most regions have rock layers other than limestone c. in most regions, the soil is too thin d. the water is too acidic enough in most places

Atemperature inversion can cause a warm air mass to move over a colder air mass. this traps the colder air mass and prevents surface air from rising. this may result in which of these? a) smog b) acid rain c) freezing rain d) a thunderstorm

How is the acceleration of an object in uniform circular motion constant? a - in magnitude only b - in direction only c - in both magnitude and direction d - in magnitude, direction & orientation