A star produces energy by: A. creating helium from hydrogen in its core

B. reflecting energy from nearby stars

C. rotating quickly on its axis

D. absorbing and releasing the matter of other stars

Dubai is challenged by all of the following environmental factors except a. a warm and dry climate b. a lack of annual rainfall c. scarce freshwater resources d. a lack of valuable natural resources

In which layer of the atmosphere are the particles so far apart that they can travel hundreds of kilometers without colliding with each other? a.exosphere b.troposphere c.mesosphere d.thermosphere

The is an exotic animal in australia that was introduced by european settlers a. koala b.kangaroo c. emu d. horse