A．Too slow for a difficult book though just right for a non-serious one.B．Too slow for a non-serious book but too hast for a difficult one.C．Too fast for difficult material though just right for a non-serious book.D．Too fast for a non-serious book as well as a difficult one.
A．Too slow for a difficult book though just right for a non-serious one.
B．Too slow for a non-serious book but too hast for a difficult one.
C．Too fast for difficult material though just right for a non-serious book.
D．Too fast for a non-serious book as well as a difficult one.