It remains to be seen North Korea will remain stable under its new young leader.
| A．when | B．whether | C．why | D．that |
In the past we lost many chances, _______ we paid little attention.
| A．which | B．that | C．in which | D．to which |
The pen, _______ I had been writing for ten years, was broken.
| A．with which | B．with that | C．as | D．with it |
Mary has two brothers, ________ are doctors.
| A．both of they | B．both of whom | C．both of them | D．whom of both |
The problem _______ you argued about yesterday has been solved.
| A．that | B．what | C．why | D．for which |
My aunt bought me a book, the name _______ I have forgotten.
| A．of it | B．which | C．whose | D．of which |