---Answer the doorbell, please. It must be your uncle. ---It Heidi. She’s coming over this morning to help me with my math.
A clean environment can help the city bid for the Olympics, which ________ will promote its economic development.
Letterboxes are much more ________ in the UK than in the US, where most people have a mailbox instead.
I’d appreciate _________ if you would like to teach me how to use the computer.
—What’s the name? — Khulaifi._______ I spell that for you?
So difficult it to work out the problem that I decided to ask Tom for advice.