Robots,___(become)increasinglyprevalentinfactoriesandindustrialplantsthroughoutthedevelopedworld,areprogrammedandengineeredtoperformindustrialtaskswithouthumanintervention.

If you had been in better health, we___ (allow) you to join them in the work.

Students should（）their own interests as well as do their schoolwork. 

Notuntilrecently_____thatThompsonhadbentellingthetruthallalong

He took his umbrella with him lest it ____(rain).