Questions & Answers about Студентка читает книгу в библиотеке.
Both mean student, but they differ by gender:
- студент – male student
- студентка – female student
The ending -к-а is a common way to form a feminine noun from a masculine one in Russian:
- учитель → учительница (teacher, m → f)
- художник → художница (artist, m → f)
So студентка tells you explicitly that the student is female.
читать is the infinitive: to read.
In the sentence we need a conjugated verb form that agrees with the subject студентка (3rd person singular, she). For the verb читать (to read), the present tense is:
- я читаю – I read
- ты читаешь – you read (informal)
- он/она/оно читает – he/she/it reads
- мы читаем – we read
- вы читаете – you read (plural/formal)
- они читают – they read
Since студентка = она (she), we use читает: Студентка читает…