He‘s working hard_____.
B
forfear(that)“惟恐，以免”，引导的从句用虚拟语气should+动词原形，should可省略。lest意思及用法类似。
Copernicus maintained that the earth_____round the sun.
The driver pulled_____at the traffic lights.
Thegirlwhofoundtheringreceivedagenerous_____offivepounds.
Mywalletisnowheretobefound.I_____itwhenIwasonthebus.
