_________ from other continents for millions of years, Australia has many plants and animals not found in any other country in the world.
| A．Being separated | B．Having separated |
| C．Having been separated | D．To be separated |
--- What’s wrong with your car?
----It has atyre.
| A．spare | B．normal | C．smooth | D．flat |
---He is fifteen years younger than you.
---?
| A．How come | B．So what | C．How then | D．if so |
Although his experiments were designed to support the ideasthe influence of environment upon plants, Mendel found that many characteristics were passed on from one generation to the next.
| A．concerning | B．attaching to | C．involving in | D．concerning with |
They are experienced porter(搬运工)who know how tothe weight of the rocks they carry.
| A．spread | B．put | C．launch | D．take |
So fastat the lecture that I missed much of it.
| A．he did speak | B．he spoke | C．did he speak | D．did he spoke |