According to the passage, in a way physicists are____.

8. Professor Hawking is ________ as one of the world's greatest living physicists.

. Physicists have made new discoveries that challenge our ______ theories of the universe.

Other physicists like Max Planck, more senior and experienced than Einstein, were closing in on the answer, but Einstein got there first. ( ) A: Other physicists like Max Planck, more senior and experienced than Einstein, had started to examine the problem much earlier than Einstein did. B: Other physicists like Max Planck, more senior and experienced than Einstein, were getting closer to the answer, but Einstein solved the problem first.

In 1932, physicists engaged in studying the atom and its nucleus had only three particles to consider: the proton, the neutron ,and the electron.

​4. Professor Hawking is ________ as one of the world’s greatest living physicists.‏​‏ A: clarified B: acknowledged C: dignified D: illustrated

Professor Hawking is ______<br/>as one of the world’s greatest living physicists. A: dignified B: clarified C: acknowledged D: illustrated

Physicists have made new discoveries that challenge our（）theories of the universe. A: existed B: adapted C: accepted D: established

Many physicists hope that physics will ultimately () why the universe has the specific laws that it does. A: explanation B: explain C: explanatory D: self-explanatory

Prof. Hoffmann told Dr. Pan that Carl Sagan, who wasa professor of astronomy at Cornell University, would be the most important scientist in modern America, not because he was _____________, but because he taught Americans to be interested in space. A: the best astrophysicist B: the best quantum physicists C: the best nuclear physicist D: the best theoretical physicist