Human beings have somehow managed to engineer the night to receive us by filling it with light. This kind of control is no different from the feat ( 壮 举 ) of damming a river. Its benefits come with_________ — called light pollution — whose effects scientists are only now beginning to study. Light pollution is largely the result of bad lighting design. _________ lighting washes out the darkness of night, altering light levels and light rhythms to which many forms of life, including ourselves, have_________. Wherever man-made light spills into the natural world, some aspects of life-migration, reproduction, feeding-is affected.

For most human history, the phrase “light pollution” would have_________. Imagine walking towards London on a moonlit night around 1800, when it was Earth’s most populous city. Nearly a million people lived there, _________ candles, torches and lanterns, as they always had. Only a few houses were lit by gas, and there would be no public gaslights in the streets or squares for another seven years. From a few miles away, you would have been more likely to_________ London than to see its dim collective glow.

We’ve lit up the night as if it were a(n) _________ country. As a matter of fact, among mammals (哺乳动物) alone, the number of species active at night is astonishing. Light is a powerful biological force, and on many species it acts as a magnet attracting them to it. The effect is so powerful that scientists speak of songbirds and seabirds being_________ by searchlights on land or by the light from gas flares on marine oil platforms, circling and circling in the thousands until they drop.

It was once thought that light pollution only affected astronomers, who need to see the night sky in all its glorious clarity. Unlike astronomers, most of us may not need a_________ view of the night sky for our work. __________, like most other creatures, we do need darkness. __________ darkness is pointless. It is as essential to maintaining our biological welfare as__________ itself; the price of modifying our internal clockwork means it doesn’t operate as it should, causing various physical discomforts. So fundamental are the regular rhythms of waking and sleep to our being that__________ them is similar to altering our center of gravity.

In a very real sense, light pollution causes us to__________ our true place in the universe, to forget the scale of our being, which is best__________ against the dimensions of a deep night with the Milky Way — the edge of our galaxy — arching overhead.

In the deepest dive in a manned submersible(潜水器), US explorer Victor Vescovo spotted and video-recorded a plastic bag and a pile of candy wrappers on the seabed.

His _________ of plastic waste 11.2 kilometers below sea level in the Challenger Deep in the Pacific Ocean, the deepest known point in the Earth’s oceans, means there is _________ on this planet plastic waste cannot reach, _________ it has been found on Mount Qomolangma and in both Arctic and Antarctic waters.

Since the patent(专利) for plastics was _________ in 1907, 8.3 billion tons of plastic products have already been produced, of which 6.3 billion have been poured into oceans _________ processing.

Most of the discarded(丢弃) plastic products _________ in the ocean. In the Pacific Ocean, plastic garbage and other waste have already formed a(n) _________ that’s 1.6 million square kilometers in size. That is the size of Mongolia.

Every year, about 8 million tons of plastic waste flow into the ocean. It is _________ that the total weight of plastic waste will reach 12 _________ tons by 2050, more than the total weight of oceanic fish.

This plastic waste __________ life in the oceans and on the land alike by filling in their stomachs so they cannot eat, or __________ around their bodies so they cannot breathe. It pollutes the __________ and prevents plants’ roots from digging deep into the ground. Plastic micro-particles(微粒) also join the water __________ and enter the bodies of animals, including humans. As humans are at the top of the food __________ , plastic micro-particles accumulate inside our bodies.

We must do something to __________ the situation. Don’t get plastic bags at the supermarket and take your own reusable one __________ . Give up fast delivery lunches and instead cook or go to the restaurant. Get into the __________ of sorting your garbage.

But that’s so much __________ said than done. Environmentalists have been __________ behavioral changes for at least three decades, yet we __________ to use a growing amount of plastic products.

Racket, din, clamor, noise, whatever you want to call it, unwanted sound is America's most wide spread nuisance. But noise is more that just a nuisance. It constitutes a real and present danger to people's health. Day and night, at home, at work, and at play, noise can produce serious physical and psychological _________. No one is immune to this stress. Though we seem to adjust to noise by _________ it, the car, in fact, never closes and the body still responds- sometimes with extreme _________, as to strange sound in the night.

The _________ we feel when faced with noise is the most common outward _________ of the stress building up inside us. Indeed, because irritability is so apparent, legislators (立法者) have made public annoyance the _________ of many noise reduction programs. The more subtle and more serious health hazards associated with stress caused by noise _________ have been given much less attention._________, when we are annoyed or made irritable by noise, we should consider these symptoms fair warning that other things may be happening to us, some of which may be damaging to our health.

Of many health hazards of noise, hearing loss is the most clearly observable and _________ by health professionals. The other hazards are harder to pin down. For many of us, there may be a risk that __________ to the stress of noise increases vulnerability to disease and infection. The more vulnerable among us may experience noise as a complicating factor in heart problems and other diseases. Noise that cause annoyance and irritability in healthy persons may have serious consequences for these already ill in mind or body.

Noise affects us throughout our lives. For example, there are __________ of effects on the unborn child when mothers are __________ to industrial and environmental noise. During infancy and childhood, youngsters affected by high noise levels may have trouble falling asleep and obtaining necessary amounts of rest.

Why, then, is there not greater __________ about these dangers? Perhaps it is because the link between noise and many disabilities or disease has not yet been __________ demonstrated. Perhaps it is because we tend to __________ annoyance as a price to pay for living in the modern world. It may also be because we still think of hearing loss as only an occupational hazard.