参考答案

正确答案：A
解析：即使一个高度现代化的国家也依然需要体力劳动。physical体力的, 身体的, 如：Staying up late makes him at his worst in terms of physical situation．熬夜使得他的体力状况处于低潮。mental心理的, 精神的, 如：This experience caused him much mental suffering．这一经历给他的精神造成极大痛苦。natural自然的, 天然的, 如：It is natural for a bird to fly．鸟, 天生就会飞。hard艰难的, 如：Life was very hard when he was jobless．失业那阵他的生活很艰难。只有physical意思上和manual最接近。