English to Russian Social Sciences Psychology психология памяти

Remembering can be described as a process of finding and retrieving information. This is easiest when
the circumstances of storage and remembering are similar. Therefore, if a student was already nervous while studying
for an exam, they may actually be able to recall the stored knowledge more effectively during the test.

Также непонятно, что означает "they" во втором предложении? Спасибо за помощь.