What kind of telescope uses only lenses?

Ineed with these last two questions: 1) what are two types of cold air masses that influence the weather in north america? name them and describe their humidity. 2) describe the motion of a cold air mass and a warm air mass and the weather you would expect at a warm front and an occluded front.

Ascrew incorporates which other simple machine? lever wheel and axle inclined plane pulley

The respiratory system removes oxygen and water from the body. select the best answer from the choices provided t f