1. He ploughed an acre in six hours.
    他六小时犁一英亩地。

2. And he estimated that there were more than 2,250,000 in one acre;
    他估计每英亩草坪里有225万多只蜘蛛。

3. At the time of the April opening of the park, which stands on a 4,800-acre site 30 kilometers (20 miles) east of Paris,
    主题公园位于巴黎以东30公里（20英里）处，占地4,800英亩。在它四月份开张时，