The island where these rare birds nest has been declared a _____.
| A．observation | B．reservation | C．preservation | D．conservation |
It was not _____ she took off her dark glassed ___ I realized she was a wellknown actress.
| A． what, that | B．until , that | C．until, when | D．when , then |
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 |