21. ----Why don’t we take a little break?

----Didn’t we just have ________?

A. it       B. that       C. one       D. this

22. The mother did not know _____ to blame for the broken glass as it happened while she was out.

A who    B when      C how        D what

23. My heart was filled with gladness because I was able to ____ my parents.

A intend    B care       C concern     D attend