If you look at a map of the Nile, you'll see it has a bunch of tributaries (Lake Victoria, Lake Kyoga, Lake Albert and Lake Tana) but those aren't where it ends, that's where it begins. The Nile River flows north because of the elevation, and it ends up in the Mediterranean Sea.<span />
B) :) ////////////////////////
Laughing can relieve muscle tension and stress. Laughing also causes your brain to release hormones like endorphins. It also decreases stress hormones, which is a big help. When you laugh you also take deep breaths, so you end up getting more oxygen in our blood stream. Laughing can also improve your immune system, so you can fight off infections better. Try to expand on that. Hope that helps.
Answer B. (Future perfect tense is used, as the sentence refers to something that will be completed by some point in the future.) is correct.
B is correct because the event which will happen in the future (the baking of the cakes) will also have ended.
I will have baked is a correct form of future perfect, because future perfect is made with the following construction:
Subject + will have + past participle
