When it ______ research into heart disease and its effects on the body, we do not have adequate substitutes for the use of animals.
| A．refers to | B．related to | C．comes to | D．talks to |
Great changes have taken place in that school, it is no longer ________ it was 20 years ago, ________ it was so poorly equipped.
| A．what; when | B．that; which | C．what; which | D．which; that |
The way he did it was different ______we were used to .
| A．in which | B．in what | C．from what | D．from which |
Some researchers believe that there is no doubt ______ a cure for AIDS will be found.
| A．which | B．that | C．what | D．whether |
The place _______ the bridge is supposed to be built should be________the cross-river traffic is the heaviest.
| A．which; where | B．at which; which | C．at which; where | D．which; in which |
The shopkeeper did not want to sell for ________ he thought was not enough.
| A．where | B．how | C．what | D．Which |