Connie's blog
http://architizer-dc.blogspot.mx/

1. Exercise
a- have lived
b- have been attending
c- had been driving
d- took
e- had worked
f- has changed
g- have been working
h- always took

2. exercise
a- has improved
b- was invented
c- applied
d- had been left
e- has changed
f- has been proved
g- have organised
h- handed in

3. Exercise
1- have you done
2- I have been working
3- I had
4- I have been teaching
5- I have always wanted
6- I have been thinking
7- I have heard
8- Have you seen
9- haven't been
10- Have you rang