Carver discounts the 17, 040-per-minute reader in the 1963 study because all the times and word counts were self-reported, and the comprehension tests were self-graded.
Aural tests are objective and can be graded mechanically.
听力测验是客观的,可以机械地评分。
3
Practical tests show that the performance of cemented carbide anvils, coated blade and drill bits with graded structure developed in this dissertation are superior to those with regular structure.