The research lacks ________ evidence, and therefore, its conclusions are doubtful.[ ]

The scientists showed great ______ the warming of the earth．

__________ the girls _________ over twenty in our class.

Has your uncle come back from England for a summer holiday —-Yes. But he _________ at home for only a few days. Now he has been back to London.

Mother went shopping; __________, Icleaned the house.