Question

Which features on mars point to the possibility of liquid water on the planet?

Answer 1

     In 2011 NASA researchers identified features on Mars known as Recuring Slope Lineae ( or RSL ). RSL are relatively dark and narrow features.They are thought to be a signs of salty liquid water on Mars. One hypothesis for RSL formation is that they form when underground bodies of salty water leak into the surface.
   Answer: Recuring Slope Lineae. 

Answer 2

gullies and stream-like channels

Explanation: correct on gradpoint