It is our duty ______much attention to ________ our best to keep our city clean.
| A．to pay, trying | B．paying, trying |
| C．pay, try | D．to pay, try |
---- I’m sorry I’m late . It’s rush hour , you know .
---- It doesn’t matter .We ___ here for just a few minutes.
| A．have arrived | B．have been | C．have come | D．have got |
I think this is the most interesting thing _____ has happened to us .
| A．that | B．which | C．what | D．who |
--- I’d like to introduce my best friend to you , Peter .
---- Thank you , Lucy . But we __________already .
| A．meet | B．met | C．will meet | D．have met |
_____ out your love . The world will become a nicer place to live in .
| A．Speak | B．To speak | C．Speaking | D．Spoke |
Success will belong to those ___ never say impossible ..
| A．whom | B．who | C．that | D．which |