Despite the great difficulty we had _____ out the plan, it paid off in the end.
| A．carrying | B．carried | C．to carry | D．carry |
All the Harry Potter books by Joanne Rowling, a poor single mother ________ in Edinburgh, ________ all over the world.
| A．lives; are well sold | B．lives; sell good |
| C．living; sell well | D．living; are well sold |
—Lily is going to make a presentation in class this afternoon.
—Oh, really? I ________ it was Michael's turn.
| A．think | B．have thought |
| C．thought | D．am thinking |
The house is dirty because it ________ since they moved out.
| A．doesn't clean | B．isn't cleaned |
| C．hasn't cleaned | D．hasn't been cleaned |
Now we have arrived at the lake. But the view I photographed that day ________ any more.
| A．doesn't exist | B．isn't existing |
| C．hasn't existed | D．hadn't existed |
Up to now, our society ________ with limited living space and a shortage of natural resources.
| A．has been challenged | B．is being challenged |
| C．is challenging | D．has challenged |