We stayed at home ________ the rain .
| A．because of | B．because | C．as | D．since |
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 |
By the time California to become the 31th federal state of the USA in 1850, it was already a multicultural society.
| A．selected | B．collected | C．existed | D．elected |