_____ from other continents for millions of year, Australia has many plants and animals not found in any other country in the world.
| A．Being separated | B．Having been separated |
| C．Having separated | D．To be separated |
There are so many books! It is not easy for us to decide what to take and what to_______.
| A．take on | B．pick up | C．leave behind | D．work out |
When I try to understand _______ that prevents so many Americans from being as happy as one might expect, it seems to me that there are two causes.
| A．why it does | B．what it does | C．what it is | D．why it is |
The science of medicine, _______ progress has been very rapid lately, is perhaps the most important of all the sciences.
| A．to which | B．in which | C．Which | D．with which |
He is _______ to get there in time if he starts right now.
| A．possible | B．probable | C．likely | D．impossible |
—Which day do you think is all right to our next meeting?
—You make _______,_______ day is all the same to me.
| A．one;one | B．it;any |
| C．that; some | D．this; another |