— Don’t you think the new job is a real challenge for Jack?
—Well, ______ difficulties he meets, I believe he will never lose heart.
| A．whenever | B．however |
| C．whichever | D．whatever |
There’s a fascinating driveout for tourists.
| A．to mark | B．to be marked | C．marking | D．marked |
His music is popular today as it ever was.
| A．very | B．as | C．such | D．so |
Cloning plants is straightforward cloning animals is very complicated .
| A．so that | B．although | C．while | D．as if |
The popularity of films such as Jurassic Park,a scientist clones several kinds of extinct dinosaurs, proves how the idea struck a mixture of fear and excitement into people’s hearts.
| A．which | B．what | C．in which | D．that |
It happens in plants when gardeners take cuttings from growing plants to make new .
| A．ones | B．one | C．others | D．other ones |