Question

what is the polar vortex?
a. a type of storm in the tropics
b. a high - pressure area above mountains
c. a warm current in the ocean
d. a low - pressure system surrounding the poles
what is the midnight sun?
a. an increase in snow during winter
b. a time of reduced temperature
c. a period of darkness during winter
d. a period of continuous daylight in summer

Explanation:

First Question (What is the polar vortex?):

The polar vortex is a large area of low - pressure and cold air that surrounds the Earth's polar regions (North and South Poles). Option a is incorrect as it's not a tropical storm. Option b is wrong because it's not a high - pressure area above mountains. Option c is incorrect as it's not an ocean current. Option d correctly describes it as a low - pressure system surrounding the poles.

The midnight sun is a natural phenomenon that occurs in the polar regions during summer. Due to the tilt of the Earth's axis, in places like Norway, Alaska, etc., within the Arctic Circle (or Antarctic Circle in the southern hemisphere), the sun remains visible at midnight. Option a is incorrect as it has nothing to do with snow increase. Option b is wrong as it's not related to temperature reduction. Option c is incorrect as it describes polar night (continuous darkness in winter), not midnight sun. Option d correctly states that it's a period of continuous daylight in summer.

Answer:

d. A low - pressure system surrounding the poles

Second Question (What is the midnight sun?):