Why must lander probes on Mars be sterilized before launch? A) ...

[bobthebuilder]

Why must lander probes on Mars be sterilized before launch?
 
  A) to prevent terrestrial microbes hitching a ride on the probe and contaminating the Martian surface
  B) to prevent terrestrial microbes destroying the electronics in the probe during its passage to Mars
  C) to prevent Martian dust from building up on the probe on the surface
  D) to prevent Martian microbes from contaminating the lander probe

Question 2

Telescopic observations of distant galaxies have shown that the universe is
 
  A) expanding
  B) contracting
  C) static and unchanging
  D) infinite in size

[snackralk]

Answer to Question 1

A

Answer to Question 2

A