He is so clever that he can solve ______ problems by himself.

依次填入下面一段文字横线处的语句，衔接最恰当的一组是（ ）中国书法艺术是中华大地上土生土长、地地道道的民族传统艺术。__________。__________，__________。__________，__________，__________，是中国传统文化的精粹体现和辉煌标本。①它至今仍是从头至尾、从里到外②始终保持着地道的中国作风与中国气派③在生成和发展的过程中，它与中国传统文化始终难解难分④唯独书法艺术的情况不一样⑤当然，中国传统文化对古往今来中国的人文、历史乃至一切事物都有深刻的渗透与影响⑥但那影响毕竟在逐渐淡化

If all of us give ________helping hand, we can make the world ________ better place.

He seems _________the homework, for he was taking a walk on the playground.[ ]

If you happen to go to that river, you’ll find it more dangerous than commonly _______.