Answer: the tree main features of a synovial joint are articular capsule, articular cartilage and synovial fluid.
Explanation:
Adenine always pairs with Thymine, and Cytosine always pairs up with Guanine in DNA. When dealing with RNA, however, Uracil replaces Thymine. So in RNA, A pairs with U and C pairs with G. (just a fun fact) :)
Bfvfjvh u ujsbeiwjbidjj jdjejejjvi
The main reason is that there is no atmosphere. This means that there is no weather and no weather means that there is no wind or rain. Wind and rain are main components of erosion and because there is no erosion, craters can stay preserved for a very long time.
Hope this helps!!