He hopes he can visit the United Nations building while he ____________ in New York next summer.
A. has been
B. is
C. will be
D. shall be
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The writer talks mostly about pictures taken _________.
A. outdoors
B. indoors
C. in color
D. for newspapers
设f(x)满足f"(x)+(f'(x))2=x且f'(0)=0，则 ( )
A. f(0)是f(x)的极大值
B. f(0)是f(x)的极小值
C. f(0)不是f(x)的极值，(0,f(0))是曲线y=f(x)的拐点
D. f(0)不是f(x)的极值，(0,f(0))也不是曲线y=f(x)的拐点
下列哪项是慢性肾炎必有的表现
A. 水肿
B. 血尿
C. 蛋白尿
D. 高血压
E. 肾功能减退
With the help of telescopes, scientists can _________.
A. discover all stars and planets in the universe
B. gain more knowledge about the universe
C. study the craters, mountains and plains on the moon's surface
D. increase our knowledge of the earth
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