—John has put forward ________ most challenging question for us to answer.
—Yes，it really is.I have never heard ________ harder one.
| A．the；/ | B．/；the | C．the；the | D．a；a |
The education of ________ young is always ________ hot and serious topic.
| A．/；/ | B．the；a | C．/；the | D．the；/ |
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 |