He _____ you as soon as he _____ back. [ ]

It’s ________pleasure for me to be invited to play the piano at the concert.

In the exam, the_________you are, the_________mistakes you’ll make.

Do you know _________ an “o” and _________ “u” in the word “computer”?

This is 3-D printer. And this is an artificial (人工的) ear. Can you believe that scientists printed this artificial ear by this 3-D printer?