It remains to be seen________North Korea will remain stable under its new young leader.
| A．when | B．whether |
| C．why | D．That |
Not until the early years of the 19th century____ what heat is.
| A． man did know | B．man knew | C．didnot man know | D．did man know |
The last time we had great fun was _____we were visiting the Water Park.
| A． where | B．how | C．when | D．why |
It was along the Mississippi River ____Mark Twain spent much of his childhood.
| A． How | B．which | C．that | D．where |
_____ their hats into the air, the fans of the winning team let out loud shouts of victory.
| A． To throw | B．Thrown | C．Throwing | D．Being thrown |
No decision____ about any future appointment until all the candidates have been interviewed.
| A． will be made | B．is made | C．is being made | D．has been made |