.Who is knocking at the door?——It ______ Mr. Black, because he_______Washington.
I think you won’t pass the coming English exam ______ you work hard from now on.
---Can you think of any_______tips to protect yourselves against crime? ---I have no idea.
Nobody has the right to laugh at others _________ he is right.
Look, there is“u” and “s” in the word university .
---Linda, is there anything else you want to know about China? ---Yes, I am still wondering _____________.