The sign reads “In case of __________ fire，break the glass and push _________ red button．”

1. A.
   不填；a
2. B.
   不填；the
3. C.
   the；the
4. D.
   a；a

The sign reads “In case of __________ fire，break the glass and push _________ red button．”

[　　]

The sign reads “In case of ________ fire, break the glass and push ________ red button.”

[　　]

The sign reads “In case of ________ fire, break the glass and push ________ red button. ”

　　A．不填; a

　　B．不填; the

　　C．the; the

　　D．a; a