| Scientists discovered that atoms of
some substances are radioactive. This means that they are unstable and can be
split. The chain of splitting atoms releases great destructive energy and it was
this discovery which led scientists to develop the idea of an atomic bomb. The
American government secretly worked to produce such a bomb and the first version
was much more powerful than anyone had thought. By this time, the World War Ⅱ had ended in Europe. But the Japanese refused to surrender, the Americans decided that by dropping an atomic bomb on Japan, they could end the war quickly and save more of their soldier’s lives. Soon after midnight on 6 August 1945, a bomb was dropped on the city of Hiroshima, a civilian target. No warning was given and there was total devastation. Almost all the buildings were destroyed and more t A. was less powerful B. was dropped in Nagasaki C. was a failure D. was tested in desert [单项选择]Citizen Scientists
Understanding how nature responds to climate change will require monitoring key life cycle events — flowering, the appearance of leaves, the first frog calls of the spring — all around the world. But ecologists can’t be(51) so they’re turning to non-scientists, sometimes called citizen scientists, for help.
Climate scientists are not present everywhere.(52) there are so many places in the world and not enough scientists to observe all of them, they’re asking for your help in(53) signs of climate change across the world. The citizen scientist movement encourages(54) people to observe a very specific research interest — birds, trees, flowers budding, etc. — and send their observations(55) a giant database to be observed by professional scientists. This helps a small number of scientists track a(56) amount of data that they would never be able to gather on their own.(57) like citizen journalists helping large publications cover a hyper-local beat, citizen scientis
A. known B. featured C. belonged D. called 我来回答: 提交
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