惟恐

zhè ge xué shēng yī zhí hěn nǔ lì wéi kǒng luò hòu

这个学生一直很努力，惟恐落后。

The student has been working hard for fear that he should fall behind.

tā pīn mìng de gàn huó wéi kǒng bèi lǎo bǎn jiě gù

他拼命地干活，惟恐被老板解雇。

He worked hard for fear that he might be fired by the boss.