Altitude increases exposure to cosmic radiation because there is (are) less __________ to act as a shield.

Question

Question: Altitude increases exposure to cosmic radiation because there is (are) less __________ to act as a shield.

Options:

1.  Clouds
2.  Air
3.  Airplanes
4.  People

Answer 1

2. Air

Altitude increases exposure to cosmic radiation because there is less air to act as a shield.