Scientists and engineers     1     (prepare) for possible travel into interstellar space, the area in between stars, in the distant future. Experts believe it will likely take many years before the technology and equipment are developed     2     (send) humans to this unexplored area of space. But if it does happen, massive spaceships     3     carry humans on long trips to distant starts.

Two American researchers, Andrew McKenzie from the University of Kansas and Jeffrey Punske of Southern Illinois University, have explored one possible problem with such travel. They considered the possibility     4     changes in human language could develop over time, thus     5     (cause) major communication problems with people on Earth.

Languages naturally change as communities grow more isolated from each other, the researchers noted in the paper. The long isolation of a community could lead to enough differences in language to make     6     impossible for community members back home to understand. The researchers noted that in    7     (add) to new words being used, the language of people traveling on spaceships and living in colonies     8     (experience) many other changes. For example, the sounds of different letters would likely change over time, affecting not only individual words, but the whole grammatioal system.

The researchers say one possible solution to     9     (limit) communication problems would be to include language experts on spaceship crews. Another suggestion is to use sign language as a form of communication. McKenzie added that space travelers might question whether it is even worth trying to learn how to communicate with people on Earth. But he believe there will always be a need, even     10     it is very limited. “You have to learn a little Earth English to send messages back, or to read the instruction manuals and information that came with the ship,” he said.

7 . One of the classic science-fiction treatments of the end of civilization was The Death of Grass, by John Christopher, in which a mysterious sickness struck down all the grasses on which most of the world's agriculture is based, from rice to wheat. Tn the end, politics among the survivors of disease, war and famine were reduced to bitter fratricidal struggle over a defensible potato patch. Like most of the so-called ''comfortable disaster" novels, this could be criticized for optimism. Depressing as a future of famine and the war of all against all might seem,   the consequences were largely limited to humans.

However, the threatened extinction of insect populations around the world raises the prospect of a much less general disaster, which would involve plants, birds, fish, small mammals, and everything else depending on insects. That's just the start. Other species, and we ourselves, depend on the animals and plants that need insects. When they go, we go. This is not just a greater disaster. It's a much more reasonable one. The most recent study has concluded that insect biomass is decreasing around the world at a rate of 2.5% a year. At that rate, half the insects in the world will be gone in 50 years' time, and all of them in a century — though no one will be keeping track of centuries then.

The chief driver of this disaster is unchecked human greed. I spite our individual and even collective cleverness, we behave as a species with as little foresight as a colony of nematode worms that will consume everything that it can reach until all is gone and it dies off naturally. The challenge of behaving more intelligently than creatures that have no brain at all will not be easy. But unlike the nematodes, we know what to do. The UN convention on biodiversity was signed in 1992, alongside the convention on climate change. Giving it the strength to hold back our appetites is now urgent. Biodiversity is not an optional extra. It is the web that holds all life, including human life.

The two main expressions of greed that speed this apocalypse are global warming and industrial agriculture. It appears that most of the damage is being done in the developed world by farming practices. The use of giant fields, lack of shelter for insects of any sort at all, whether they are harmful to human interests or not, and where the plants are drenched in long-lasting pesticides, is fatal for uncounted billions of insects. The effects of this kind of forming reach beyond the fields immediately affected, too. There has been a huge loss of aquatic insect species from the rivers into which the products of industrial agriculture are flushed by rain. Even in German nature reserves, which are by definition protected from the use of pesticides, there have been sleep falls in insect populations because so many of the most widely used ones are persistent and prevent breeding.