"use" or "use up" or "spend"

Only 'spend' collocates well here.

But in the test, "use up" was the answer and I asked myself why "use up"? why not "spent"? Then again, I saw no difference between "use" and "use up". So "use up" is an answer.

youzouBut in the test, "use up" was the answer

Then the test key was wrong. The test was written by a non-native speaker, was it not?

"Use up" is the best answer, as the sentence implies some consternation on the speaker's part. The speaker feels that the job of marking monopolizes the time he has available. "Spend" is more matter-of-fact and does not have this implication of irritation on the speaker's part. "Use" is not possible here and is ungrammatical.

Anonymous the sentence implies some consternation on the speaker's part. The speaker feels that the job of marking monopolizes the time he has available.

No, the sentence does not. It simply states that s/he spends all his/her time marking. You have decided to read all of that into it yourself. In addition, 'use up' is a phrase we use for consuming extra q

Mister Micawber youzouBut in the test, "use up" was the answerThen the test key was wrong. The test was written by a non-native speaker, was it not?

That is for ESL program of university of Victoria - Canada

Mister Micawbernot one of your better posts, Summit.

I think this sentence is ironic, but I couldn't understand the structure of sentence and so I couldn't understand the meaning, and summit with upper-case 'S'?!

youzouI think this sentence is ironic, but I couldn't understand the structure of sentence and so I couldn't understand the meaning, and summit with upper-case 'S'?!

I see that you are still having trouble with irony, youzou. Nothing ironic at all: I meant it at face value. 'Summit' (I use a locational term from the anonymous poster's IP address as his nickna