The question that puzzled them is ____ they can get rid of the air pollution in the area.
| A．how is it that | B．that how | C．that it is how | D．how it is that |
A clean environment can help the city bid for the Olympics, which ________ will promote its economic development．
| A．in nature | B．in return | C．in turn | D．in fact |
Letterboxes are much more ________ in the UK than in the US, where most people have a mailbox instead．
| A．common | B．normal | C．ordinary | D．usual |
I’d appreciate _________ if you would like to teach me how to use the computer．
| A．that | B．it | C．this | D．you |
—What’s the name?
— Khulaifi．_______ I spell that for you?
| A．Shall | B．Would | C．Can | D．Might |
So difficult it to work out the problem that I decided to ask Tom for advice．
| A．I did find | B．I have found | C．did I find | D．have I found |