lǎo shī / jiǎng / de / nèi róng / tài / shēn ào / xué sheng men / tīng / de / bàn dǒng bù dǒng / yī liǎn / máng rán

老师讲的内容太深奥，学生们听得半懂不懂，一脸茫然。

The teacher's explanation was too profound; the students only partly understood and looked bewildered.