1. She ______ (read) a book now.

Explanation:

The sentence includes the word 'now', which indicates an action happening at the present moment. Therefore, the present continuous tense is used.

Solution:

The present continuous tense is formed using the auxiliary verb 'to be' (am, is, are) followed by the present participle of the main verb (verb + -ing).

1. Subject: She (third person singular)
2. Auxiliary verb: is
3. Main verb: read + -ing = reading

Answer: is reading