1. I think I've lost my coat button trying___ on the bus in that crowd, so I need ___one that matches the others.
a. getting/finding
b.to get/to find
c.get/find
d. to getting/to have found
2. I will never forget ___in that snowstorm for hours.
a.driven
b.to be driving
c.driving
d.to drive
3. The Himalayas are known___for the past fifty million years.
a. to have been rising
b. to rise
c. having risen
d. having been rising
4. They seemed ___about us because they kept___at us while they were talking.
a. gossip/to have been looking
b. to have been gossiping/looking
c. to gossip/looked
d. to be gossiping/looking