下列有关质粒的叙述，正确的是（ ）
| A．质粒是细菌细胞中能自主复制的小型环状DNA分子 |
| B．质粒只有在侵入宿主细胞后才能在宿主细胞内复制 |
| C．细菌质粒的复制过程一定是在宿主细胞外独立进行的 |
| D．质粒是广泛存在于细菌细胞中的一种颗粒状的细胞器 |
______ happy I am to have you in the party!
| A．Why | B．What | C．How | D．Well |
______ the end ______ last term we had a party.
| A．In; opposite | B．At; of | C．From; to | D．During; with |
My sister plays the piano ______ than me.
| A．worse | B．bad | C．badly | D．worst |
This is a ______ season.
| A．rainy | B．rain | C．rainning | D．rained |
Can he do it ______?
| A．he | B．his | C．him | D．himself |