---Which do you prefer, paper books or e-books?
---My parents only allow me to read paper books. They _______ my eyes.
A. talked about B. have heard about
C. are learning about D. worry about
---Which do you prefer, paper books or e-books?
---My parents only allow me to read paper books. They _______ my eyes.
A. talked about B. have heard about
C. are learning about D. worry about
D