Question

talk to your classmate ( COMO FICA CADA FRASE) URGENTE​

Answer 1

Pelo que me parece, basta substituir a palavra "for" por "since" e continuar a frase com a oração dentro dos parênteses. Então, o correto seria:

1. This masterpiece has been at the art gallery for two months. (since August)

This masterpiece has been at the art gallery since August.

2. My brother has been a rap singer for 15 years. (since he was a teenager)

My brother has been a rap singer since he was a teenager.

3. That paiting has been at my grandma's house for 30 years. (since the 80's)

That paiting has been at my grandma's house since the 80's.

4. She has been here for five hours. (since 8:00 a.m.)

She has been here since 8:00 a.m.

5. My best friend has been a trainee at the company for one year. (since 2017)

My best friend has been a trainee at the company since 2017.

Não vou colocar todas as frases aqui pois estou num intervalo e ele vai acabar já já, mas acho que deu pra você pegar a ideia da atividade.