Jack________doing________homework．
| A．is，her |
| B．is，my |
| C．isn’t，his |
| D．isn’t，my |
Nancy with her friends________now．
| A．play |
| B．plays |
| C．is playing |
| D．are playing |
Listen！Who________behind the tree？
| A．sings |
| B．sing |
| C．singing |
| D．is singing |
My brother left school in 2005，and since then he________in Beijing．
| A．lives |
| B．lived |
| C．will live |
| D．has lived |
We didn’t start our discussion________everybody arrived．
| A．since |
| B．if |
| C．while |
| D．until |