Answer:
Adenine - Thymine
Guanine - Cytosine
Thymine - Adenine
Cytosine - Guanine
Explanation:
A goes to T, and vice versa. C goes to G, and vice versa. No matter how many times you flip a strand of DNA, A will always go with T and C will always go to G.
If it helps you, C and G are both curved letters and look very similar to each other. That's how I remembered that they went together. :)
