9. There have been many UFOs ________ reported.

A. sightings                

B. signs

C. signals

D. sights

10. Your sister doesn't work in a foreign company, ________?

A. is she         

B. does she

C. was she

D. did she

11. Nam: “Let's go to the beach this weekend.” - Son: “________”

A. You're welcome.

B. That’s a good idea.

C. Have a good trip.

D. It's my pleasure.