Most computer users have never received any formal keyboard training. Consequently, their keyboard skills are inefficient.大多数的计算机用户都没有经过正规的键盘训练，因此他们的键盘技巧效率不高。His inefficiency is a black mark against him.他工作效率不高，这是对他不利的一个短处。Firstly, they are not efficient, and secondly, they are expensive to make.首先，它们效率不高; 其次，它们的制作成本很高。