[误] The game is at hand and every athlete is training hard to improve their previous records.

[正] The game is at hand and every athlete is training hard to improve on their previous records.

注：improve 指“改善，提高”，如 improve one\'s language ability（提高某人的语言能力）。在英国人看来，以前的纪录（previous records）是既成事实，不可能再加以改变（improve）了，所以应该在 improve 后面加上介词 on，以表示创造新的、更高的纪录。