quē / shǎo / zhēn / shí / àn / lì / de / jiǎng / jiě / xiǎn / de / suǒ / rán / xué / shēng / hěn / nán / jí / zhōng / zhù / yì / lì

缺少真实案例的讲解显得索然，学生很难集中注意力。

The explanation, lacking real examples, seemed dry, making it hard for the students to stay focused.