Soluzione del esercizio 6 di Identity B1+

Esercizi svolti per il libro Identity B1+

Soluzione

  1. Scientists have been investigating global warming for years.
  2. William has been donating food to charity.
  3. You haven't been listening to me!
  4. Has Katy been studying all morning?
  5. I haven't been feeling very well.
  6. What have you been working on?