A task of the post office staff is to_ (class) mail according to the places it is to go

Robots, ___(become) increasingly prevalent in factories and industrial plants throughout the developed world, are programmed and engineered to perform industrial tasks without human intervention.

At the end of the conference, all the_(participate) were asked to fill out a questiolmaire

Thetheoryofblackholesinspace__(accept)bymanyseriousscientistsandastronomers.

Manyothernewtechniquesarenowavailablethatenablemoreresearch___(do)inthetesttubetoseeifchemicalsproduceharmfulbiologicaleffects.