According to the Base Pair rule, Cytosine always pairs with

Guanine always pairs with Cytosine. :)

lunar landing mission. apollo 11 was the first manned mission to land on the moon. the first steps by humans on another planetary body were taken by neil armstrong and buzz aldrin on july 20, 1969. the astronauts also returned to earth the first samples from another planetary body.

explanation:

so whats the answer