We've considered several ways of paying to cut in line: hiring line standers, buying tickets from scalpers (票贩子), or purchasing line-cutting privileges directly from, say, an airline or an amusement park. Each of these deals replaces the morals of the queue (waiting your turn) with the morals of the market (paying a price for faster service).

    Markets and queues—paying and waiting—are two different ways of allocating things, and each is appropriate to different activities. The morals of the queue, “First come, first served, have an egalitarian (平等主义的) appeal. They tell us to ignore privilege, power, and deep pockets.

    The principle seems right on playgrounds and at bus stops. But the morals of the queue do not govern all occasions. If I put my house up for sale, I have no duty to accept the first offer that comes along, simply because it's the first. Selling my house and waiting for a bus are different activities, properly governed by different standards.

    Sometimes standards change, and it is unclear which principle should apply. Think of the recorded message you hear, played over and over, as you wait on hold when calling your bank: “Your call will be answered in the order in which it was received.” This is essential for the morals of the queue. It's as if the company is trying to ease our impatience with fairness.

    But don't take the recorded message too seriously. Today, some people's calls are answered faster than others. Call center technology enables companies to “score” incoming calls and to give faster service to those that come from rich places. You might call this telephonic queue jumping.

    Of course, markets and queues are not the only ways of allocating things. Some goods we distribute by merit, others by need, still others by chance. However, the tendency of markets to replace queues, and other non-market ways of allocating goods is so common in modern life that we scarcely notice it anymore. It is striking that most of the paid queue-jumping schemes we've considered—at airports and amusement parks, in call centers, doctors' offices, and national parks—are recent developments, scarcely imaginable three decades ago. The disappearance of the queues in these places may seem an unusual concern, but these are not the only places that markets have entered.

人体内的遗传物质彻底水解后，可得到（　　）