1. have been recently spotted

Uzasadnienie: strona bierna w czasie present perfect - has/have been + past participle.

2. was seen

Uzasadnienie: strona bierna w czasie past simple - was/were + past participle.

3. have just been found

4. have been recently photographed

Uzasadnienie (3, 4): strona bierna w czasie present perfect - has/have been + past participle.

5. are regularly lost

Uzasadnienie: strona bierna w czasie present simple - is/are + past participle.

6. are currently being investigated

Uzasadnienie: strona bierna w czasie present continuous - is/are + being + past participle.

7. had been completely abandoned

Uzasadnienie: strona bierna w czasie past perfect - had been + past participle.