Last term our maths teacher set so difficult an examination problem _____ none of us worked out.

won’t have anyone _______ in here. _________breaks the regulation will get punished.

John ________ the English club in 2012.

. He was determined not to be the first_____________it.

Lunar Probe( 月球探测器) Chang’e-5________ into space this year. It will land on the moon and return with lunar samples(样品).