1. D. Milk and sugar are non-countable nouns, although in the context of coffee, you will sometimes hear "two sugars". You can also say two sugar packets, two sugar cubes.
6. A. "Three fishes" is not grammatically incorrect, but it's seldom used.
7. B You don't want an entire chicken in your sandwich, you just want some.
9. In my opinion all of the choices are bad. D is the best of them. It's more common to ask "How much homework did the teacher give?" or "How many homework assignments..."
11. Either A or C is possible. I suspect the answer is meant to be A.