She said she was glad the difficulty had been _____.
| A．cleared away | B．cleared up |
| C．broken away | D．broken down |
_______ there are many different types of food, some animals spend their lives eating only one type.
| A．Since | B．Unless |
| C．Once | D．While |
As the Internet has gained popularity, there has been a change in the way ______ people spend their time.
| A．which | B．in which |
| C．where | D．when |
—Which city is the first ________ plastic shopping bags?
—As far as I know, it is San Francisco.
| A．banned | B．ban |
| C．banning | D．to ban |
By the time Dave reached the small boat, a thick white fog _______ over the surface of the water.
| A．spread | B．has spread |
| C．had spread | D．was spreading |
At the root of volunteering is the idea ________ one person may have the ability to offer services that can help other people.
| A．that | B．what | C．which | D．/ |