Experiments of this kind ___in both the U．S and Europe well before the Second World War

Stop that foolish clapping_____ from you and you’llcelebrate Christmas by losing your position!

The world is full of wonders, _____ we open our eyes to see them ?[ ]

There’s lots of white snow but there aren’t ______ tourists.

He kept only 2000 yuan of the prize money . Therest ________ given to charity.