Did you see
haven't met
arrived
was doing
will he be
have studied
are waiting
lived
got
has taught
graduated
c - b - b - a - c
since -> for
played -> were playing
started writing -> written
when -> since
do -> done
c - b - a -b - c - a - b - a - d - b
Now she is a teacher. She has worked as a teacher for ten years
Nam has finished his homework already
She didn't do her homework last Sunday
My sister was watching TV at 9 o'clock last night
What is your father doing at the moment?