2. It must be sent up

Be proud of

Step 4 dream of going

5. There is no doubt

6. used to send letters

7. You can't be alone anymore

Make a contribution to

9. May be cloned

10. Already logged in.

Can't wait

Similar to ours.

Take him to the airport.

Where are you going?

They had trouble with their calculations.

Quit smoking

Be a mature person

18. is made up of

Be surprised at ...

20. Believe until I see it with my own eyes

2 1. Food or drinks are not allowed in the library.

Pro: I wish you progress in your study! Hope to adopt, thank you!