Although all IELTS test materials are pretested and trialed before being released as live tests, there are inevitably minor differences in the difficulty level across tests.

• 尽管在成为正式的考题之前，所有的雅思考试素材都要经过预测试和测试；所有通过测试的考试素材，在难度水平上，不可避免的存在一定的差异。