We arrived in Barcelona _____ January.
I do my homework ______ the evening.
She left school ______ 1999.
They usually go on holiday ______ summer.
He stays with his family _____ Christmas.
I play tennis ______ the weekend.
They go to sleep ______ night.
He was born ______ April 10.
There were many inventions ______ the twentieth century.
Summer begins ______ June 21.