单选题 .  The world is undergoing a great transition marked by uncertainty and complexity which we do not yet understand.
    This poses (提出) a challenge to young people all over the world, for in about 15 years' time youth will play a fundamental role as never before in the history of the world. Young people will make up over half the population in developing countries—the so-called countries of the South. In the North they wm have the heavy responsibility of providing for societies in which elderly people will generally be in the majority. It is probably not by chance that young people in different parts of the world today represent a movement of challenge and pressure which is shaking government and attempting to impose new values in a universe which they perceive as inhospitable (冷淡的) or even hostile.
    We have come a long way from the early 20th century concept of perpetual 3% annual growth, which fitted so well with the Newtonian vision of the world-a vision resting on the idea of a perfect giant clockwork mechanism. The dramatic nature of today's crisis is based on our difficulty in understanding—on a lack of intelligibility (可理解性). For in evolution's constant march towards complexity we have just crossed a threshold. Beyond this threshold, everything is different; everything invites us to look anew (重新). But we are prisoners of images which still inhabit our minds because they brought us so much intellectual comfort in understanding our world as it used to be. Prigonine takes us over the threshold and forces us to enter into the new dialogue which is necessary. It is useful to try to transfer this new vision into the spheres of management, business, national sovereignty, and international organization. In this way we may perhaps make progress in governing that which, on first analysis we may judge to be ungovernable.1.  The characteristic of the present age of the world is ______.