tā / shū / yú / fáng / fàn / méi / yǒu / jí / shí / fā / xiàn / mén / suǒ / yǐ / jīng / huài / le

他疏于防范，没有及时发现门锁已经坏了。

He had let his guard down and failed to notice that the door lock was broken.