Students ______ remain in their seats until all the exam papers have been collected.[ ]

TV was first shown in 1929 It tookmore than two decades, ________， until 1951, forcolor broadcasts to begin in the USA

What about _________ job——It’s too difficult _________ job for me.

Why was it ______ you were so angry—Because we failed to take part in the basketball match.

I called you last night but you were not in. — Yes, I dinnerwith my parents in the restaurant then.