Nobody believed a 92-year-old man could run a marathon_______he passed the finishing line. People of all ages can challenge themselves.
| A．if | B．since | C．until | D．unless |
Do you know the Three Gorges Dam is the largest hydro-electric dam ever_______?
| A．constructed | B．constructing |
| C．to be constructed | D．been constructed |
English is a language shared by several different cultures, but each of ______ uses it somewhat differently.
| A．which | B．what | C．them | D．whom |
Have you ever had the case _______ you can’t recognize your friend’s voice on the phone?
| A．which | B．that | C．where | D．when |
He made another wonderful discovery,_____ of great importance to science.
| A．which I think is |
| B．which I think it is |
| C．which I think it |
| D．I think which is |
When the poor old lady tried to ______ the cup on the shelf to have a drink, she ______.
| A．reach for; fell down | B．reach; fell down |
| C．reach for; had fallen down | D．reach; was falling down |