Broadleaved plants in the temperate zones begin to shed their leaves before winter because they cannot______.

A．They think writers have wealth and fame.
B．They like writing.
C．They want to enjoy loneness.
D．They follow some examples.

A．What the man’s plans are for tonight.
B．Why the man does not want to play tennis.
C．Why they do not have time to play tennis after class today.
D．What time they can meet in the library.