bla__board

[　　]

A. c　　　B. ch　　　C. ck　　　D. k

— ____can we board our plane? — In twenty minutes.

  A.How soon               B.How long             C.How often

______the black board，please．

1. A.
   Look in
2. B.
   Look on
3. C.
   Look at
4. D.
   Look

— ____can we board our plane? 

— In twenty minutes

1. A.
   How soon
2. B.
   How long
3. C.
   How often