Answer:
The correct answers are:
1. Have not phoned / have been really busy.
2. Have been.
3. Has not been.
4. She has known.
5. I have read.
Explanation:
The present perfect verb tense is used for the following things:
This verb tense is formed by the auxiliary verb "to have" and a verb conjugated in past participle. If the verb is regular, "ed" will usually be added at the end. Whereas if the verb is irregular, you must learn each of the verbs so as not to make mistakes.
In this way, this verb tense is formed as follows:
I have + past participle
He
She has + past participle
It
We
They have + past participle
You