Nature is like the mechanism in an enormous clock. Everything is neatly arranged and inter connected. Every individual has its place and its function. Take the wolf for example. As meat-eaters, wolves regulate the number of plant eaters so that they do not multiply too rapidly. All animals and plants are held in a delicate balance.

The wolves remind me of a story from my childhood when my grandfather gave me an old clock. The first thing I did was take the clock apart to find out how it worked. Even though I was convinced that I knew how to put it back together in working order, I couldn’t do it. After I rebuilt it, there were a few cogs (轮齿) left over and a grandfather who was not in the best of moods. In the wild, wolves play the role of such cogs. If we remove them, not only do the enemies of sheep and cattle disappear, but the mechanism of nature also begins to run differently, so differently that rivers change course and many local bird species die out.

And things can also go wrong when a species is added. For example, the introduction of a nonnative fish leads to a massive reduction in the local deer population. Because of a fish? The earth’s ecosystems, it seems, are a bit too complex for us to draw up simple rules of cause and effect. Even conservation measures can have unexpected results. Who knew, for example, that recovering crane (鹤) populations in Europe would affect the production of Iberian ham?

So it’s high time we took a good look at the interconnections between species both large and small. It’s important for us to realize that even small interventions(介入)can have huge consequences, and we’d do better to keep our hands off everything in nature that we do not absolutely have to touch.

【小题1】What does the underlined word “regulate” mean in paragraph1?

A．Control.

B．Count.

C．Record.

D．Increase.

【小题2】What does the author want to show with the story in paragraph 2?

A．Curiosity kills the cat.	B．Grandfather’s love lasts.
C．Clocks are complex.	D．Every part counts.

【小题3】Why can things also go wrong when a species is added?

A．Local species die out due to the nonnative one.

B．Rules of cause and effect are obvious in nature.

C．The interconnections in nature are complicated.

D．Conservation projects are too hard to complete.

【小题4】What does the author suggest people do?

A．Show mercy to small animals.	B．Stay away from conservation.
C．Take a new look at meat-eaters.	D．Think twice before stepping in.