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US President Barack Obama made his first visit to China early this week, during which he sent out signals to China that the US sees China as its partner, not a rival.
During his Asian tour, Obama emphasized that the US isn't  looking to contain the rise of a strong, prosperous China.
“China-US relations are very important. Maintaining such ties  is the responsibility of both sides,” President Hu jintao told reporters after his meeting with Obama. Hu described the meeting as candid(坦诚的), constructive and fruitful, a “very good” talk.                 
The two leaders agreed that the key to China-US relations was  to respect each other's interests and major concerns, but that  national differences were normal.
A joint statement released after the meeting said it covered major issues, from nuclear proliferation to global warming to  financial crisis and trade protectionism. “China-US relations go beyond any single issue,” said Obama.
China holds a large amount of US government debt – over $800  billion (5.5 trillion yuan) in Treasury bonds. Just before  Obama's China visit, The New York Times described it as a trip  to “pay his respects to his banker”.
The US is the China's biggest export market, accounting for more  than 70 percent of China's exports. Total trade between the  two was worth $400 billion (2.7 trillion yuan), in 2008.
In addition to the financial interdependence, there are  educational exchanges to be considered. More than 11,000  Americans studied in China last year, for a 25 percent    increase over the previous year, according to the Institute of  International Education in the US. Meanwhile, Chinese students are the second largest group of  foreign students in the US, and their numbers are on the rise. Last year, 81,000 mainland students went to the US, a 20 percent increase from 2008. According to the joint statement issued on Tuesday, for the next four years, over 100,000 American students will be sent to the China for study.
Still, people in the two countries may have a long way to go in improving their opinions.
49.What’s the text mainly about?
A The significance of Obama’s visit to China
B The effects of Obama on China –US relations.
C How the two leaders solve the political and financial problems between each other.
D The educational exchanges between the two countries.
50. What does the underlined sentence in the second paragraph mean?
A The US is looking forward to becoming as prosperous as China.
B Obama believes China is the most prosperous country in Asia.
C Obama’s government sees China as its partner,not a rival.
D Obama  emphasized China would be more prosperous than the US in the future.
51.How many major issues did the meeting cover according to a joint statement?
A Three  B  Four  C  Five  D Six
52. We can infer from the text_____________
A China is the largest debtor of US government in terms of treasury bonds
B Obama  expressed his strong wish to visit China again
C Chinese students are the largest group of foreign students in America since 2008
D Although the two countries have made progress in cooperation ,national differences still exist.