Visit the professor on their office hours and explain to them that you didn t have enough time to finish the test. Maybe the Prof. will give you credit, it's worth a try. This maybe helpful. When an Prof. has 150 papers to grade, they tend to get lazy. The Prof. may think that you were just confused.
Professors also stop reading the question and read only the answer.
They tend to forget what the question was. Giving a answer is 100 times better that leaving it blank. Also, Prof. s want to grade the paper well, but naturally, they have better thing to do. What may help is underlining key words. It becomes a natural reflex to just skim the paper and just look at the terms.