I.Fill in the blank with although, and, because, but, or, since, so, unless, until, when.
1) when
2) because
3) until
4) unless
5) since
6) for
7) but
8) so
9) when
10) or
11) because
12) because
13) so
14) of
II. Find and correct the mistakes
1) have ⇒ has
2) finish ⇒ finished
3) forget ⇒ have forgotten
4) just graduates ⇒ has just graduated
5) am ⇒ have been
6) not come ⇒ hasn't come
7) reads ⇒ has read
8) wait ⇒ have been waiting
forgets ⇒ has forgotten
9) rests ⇒ has been resting
10) have ⇒ has
is ⇒ has been
III. Rewrite the sentences.
1) We haven't seen her since Christmas day
2) This is the first time I have eaten this kind of food
3) It has rained an hour
4) The last time I visited my grandparents was two months ago
5) I began studying English three years ago
6) It's nearly five years since my brother has last seen his best friend
7) How long have you learned English ?