The future of global politics will be shaped by the competition between democratic and authoritarian systems.
气候变化是我们这个时代最大的挑战之一,我们必须立即采取行动。
80% of life's most defining moments take place by age 35.
虽然触觉遍布在全身的表皮上,但是我们往往给予孩子的活动却局限于的部分。