________ astronauts go on spacewalks, they wear spacesuits to keep themselves safe.
Though
Till
When
Unless
—Excuse me.Could you tell me________get to the nearest post office? —Sorry,I am new here.
—Why is the shop still closed?It is already ten o’clock. —Because the owner is on holiday today.You can come again tomorrow afternoon________2:30 and 6:00.
—Look at my stamps. —They are beautiful!You’ve got a wonderful________.
—Can you cook by________? —Yes,I can cook well.
I’d like to see you whenever it’s________.