He is used to to his office in spite of bad weather.
| A．to walk | B．walking | C．walked | D．has walked |
As ________ unemployment is very high at the moment，it's very difficult for people to find ________ work.
| A．the；/ | B．/；/ | C．the；a | D．an；the |
The operation is ________ success and the patient is now out of ________ danger.
| A．a；the | B．a；/ | C．/；the | D．/；/ |
—Have you seen ________ pen？I left it here this morning.
—Is it ________ black one？I found it in the corner.
| A．a；the | B．the；the | C．a；a | D．the；a |
Keeping a diary is ________ good habit，by which you'll make ________ great progress in writing.
| A．a；a | B．a；/ | C．the；a | D．the；/ |
I don't know who invented ________ iphone，but I think it is ________ useful invention.
| A．the；a | B．the；the | C．an；the | D．an；a |