It was with great joy _____ he received the news that his lost daughter had been found.
| A．because | B．which | C．since | D．that |
The first thing ________ I did was to see if there were any products ________ might help me, but there only seemed to be powders ________ to kill snakes.
| A．that; /; designed | B．which; that; designed |
| C．/; that; designed | D．/; which; design |
________ is very important in doing any scientific work.
| A．Album | B．Category | C．Accuracy | D．Assume |
All efforts of cloning an animal will be ________ if there is not enough diversity in the group to overcome illness.
| A．in need | B．in place | C．in vain | D．in case |
It was the building of the rail network from the west to the east coast ________ brought even larger numbers to California in the 1860s.
| A．that | B．what | C．how | D．which |
_______ from the top of the mountain, we found the city more beautiful.
| A．Seen | B．Having been seen | C．Seeing | D．Being seen |