Atalanta erat filia regis Schoenei. haec puella, quae celerrime currere poterat, in mediis silvis habitabat. olim rex Atalantam rogavit ut maritum inveniret.

The easiest way to go about answering the early comprehension questions is to attempt to just translate the passage and if you get stuck to make an educated guess based on what you can understand and what you get infer from the question. (a)  What was Atalanta able to do? (3) Here we need to look at the relative clause following "haec puella" which is referring back to Atlanta. The Question is worth three marks so you can tell that you need to get three pieces of information out of the clause. We can see that the clause follows the structure of "possum" + the infinitive (you could also work this out from the question). Knowing "currere" is then a vocab question and the hard bit of the section comes in celerrime. You can work out from context and from the ending that this is an adverb and from the double "r" that it is a superlative. Once you work this out you can work out that it means very quickly.  

Hence for three marks (as the mark scheme tells you too): Atlanta was able to run(1) very(1) quickly(1).