Questions

Africa is the second largest continent both by popolation and area wise. Asia being first by both popolation and area wise.

DNA is the genetic material in the cell. 

Hence, option B) DNA is located in the nucleus best matches the description with the genetic material.

Compressions and Rarefactions are characteristic of Longitudinal waves.

The direction of vibration of the particles is in the same plane as in which the wave is propagating. The particles vibrate back and forth, about their mean positions.

In scouts, the military and most outdoor books or schools teach the COLDER principal. It is a great acronym for caring and using you clothing.

C - keep your clothing CLEAN. Dirt can break down the fibers of your clothing.

O - don't OVERHEAT. Sweat can lessen the effectiveness of clothing.

L - wear you clothes LOOSE and in LAYERS. Makes your system versatile.

D - stay DRY.

E - EXAMINE your clothing. Look for worn or damaged areas of you clothing.

R - REPAIR any damage that is found.

Wherever on earth we hold a compass, the needle points towards the magnetic North Pole. A compass is a great tool for navigation.

Compass is widely used in aircrafts, ships, military services,...

Every line has an upper limit and a lower limit on the frequency of signals it can carry. This limited range is called the bandwidth