—Is there anything else to discuss? — ______, I guess.

Math is the subject ______.

When he spoke, she had an unpleasant ______ into what life would be like as his wife.

Peter had intended to take a job in business, but ______ that plan after the unpleasant experience in Canada in 2010.

The company went ______ because of its poor management.

In the 1950s, the pioneers of artificial intelligence (AI) predicted that, by the end of this century, computers would be conversing with us at work and robots would be performing our housework. But as useful as computers are, they're nowhere close to achieving anything remotely resembling these early aspirations for humanlike behavior. Never mind something as complex as conversation: the most powerful computers struggle to reliably recognize the shape of an object, the most elementary of tasks for a ten-month-old kid. A growing group of AI researchers think they know where the field went wrong. The problem, the scientists say, is that AI has been trying to separate the highest, most abstract levels of thought, like language and mathematics, and to duplicate them with logical, step-by-step programs. A new movement in AI, on the other hand, takes a closer look at the more roundabout way in which nature came up with intelligence. Many of these researchers study evolution and natural adaptation instead of formal logic and conventional computer programs. Rather than digital computers and transistors, some want to work with brain cells and proteins. The results of these early efforts are as promising as they are peculiar, and the new nature-based AI movement is slowly but surely moving to the forefront of the field. Imitating the brain's neural network is a huge step in the right direction, says computer scientist and biophysicist Michael Conrad, but it still misses an important aspect of natural intelligence. 'People tend to treat the brain as if it were made up of color-coded transistors', he explains, 'but it's not simply a clever network of switches. There are lots of important things going on inside the brain cells themselves.' Specifically, Conrad believes that many of the brain's capabilities stem from the pattern recognition proficiency of the individual molecules that make up each brain cell. The best way to build an artificially intelligent device, he claims, would be to build it around the same sort of molecular skills. Right now, the notion that conventional computers and software are fundamentally incapable of matching the processes that take place in the brain remains controversial. But if it proves true, then the efforts of Conrad and his fellow AI rebels could turn out to be the only game in town.

He seemed persistent and ______ no matter what happened.

One of our rules is that every student ______ wear school uniform while at school.

The beauty of Venice, which fascinates all the visitors, ______ the style of its ancient buildings.

—There were a dozen pens in this house, but I can hardly find one now. — ______. One is sure to turn up.

—What are you going to do this weekend? — ______. If time permits, I may go to Shanghai with my friends.

Try to ______ your parents who were honest hardworking people.

They have ______ the dance many times for the better effect before they performed in the theater.

I'm not sure whether I can gain any profit from the investment, so I can't make a(n)______ promise to help you.

Earthquakes may rightly be ranked as one of the most destructive forces known to man: since records began to be written down, it has been estimated that earthquake-related fatalities have numbered in the millions, and that earthquake-related destruction has been beyond calculation. The greater part of such damage and loss of life has been due to collapse of buildings and the effects of rockslides, floods, fire, disease, tsunamis(gigantic sea waves), and other observable events resulting from earthquakes, rather than from the quakes themselves. The great majority of all earthquakes occur in two specific geographic areas. One such area covers the Pacific Ocean and its bordering landmasses. The other extends from the East Indies to the Atlas Mountains, including the Himalayas, Iran, Turkey, and the Alpine regions. It is in these two great belts or zones that ninety percent of all earthquakes take place; they may, however, happen anywhere at any time. This element of the unknown has for centuries added greatly to the dread and horror surrounding earthquakes, but in recent times there have been indications that earthquake forecast may be possible. By analyzing changes in animal behavior, patterns of movements in the earth's shell, variations in the earth's force of attraction, and the frequency with which minor earth shakes are observed, scientists have shown increasing success in expecting when and where earthquakes will strike. As a result, a worldwide earthquake warning network is already in operation and has helped to prepare for(and thus lessen)the vast destruction that might otherwise have been totally unexpected. It is doubtful that man will ever be able to control earthquakes and get rid of their destructiveness altogether, but as how and why earthquakes happen become better understood, man will become more and more able to deal with their possible damage before they occur.

Only when he started to explain ______ the reason for this.

—Sorry, I'm late. I got stuck in traffic. — ______. You're here now. Come in and sit down.

People who can't ______ between colors are said to be color-blind.

When he was in high school, hardly anyone did scientific experiments, much less accepted training ______ this respect.

You and I could hardly understand each other, ______?