血清型IgA占总Ig的（） A.5％～10％ B.20％～25％ C.15％～20％
题型：单项选择题
问题：
血清型IgA占总Ig的（）
A.5％～10％
B.20％～25％
C.15％～20％
D.[0％～15％
E.1％～5％
题型：单项选择题
| 阅读理解。 | ||
| NANJING, June 13, 2009 (Xinhua)-China will see the longest total solar eclipse (日食) in 500 years on July 22, a scientist said Saturday.
such as Tibet, Hunan and Jiangsu, will be able to witness the total solar eclipse, while in most parts of Shanghai, viewers can also see the fantastic phenomenon. For viewers in other provinces, including Beijing, they can observe a part of the eclipse, he said. A solar eclipse occurs when the moon is caught between the sun and the earth while each of them moves along their fixed orbits. In a total solar eclipse, the sun, the moon and the earth are directly in a line as the sun swings into the shadow cast by the moon. Wang said the next total solar eclipse that can be seen in China will fall on March the 20th, 2034. "But it can only be seen in-remote provinces, such as Tibet and Qinghai. It cannot not be compared with the upcoming one- in terms of time of lasting and number of cities that can see the eclipse," he added. The last total solar eclipse visible in China took place on the first of August last year. It was observed in northwest China and lasted two minutes in Yiwu County of north-western Xinjiang, the best place to see the phenomenon. | ||
| 1. According to the report, the total eclipse on July the 22nd will last _____. | ||
[ ] | ||
| A. over a month B. about 38 minutes C. about 6 minutes D. less than 30 minutes | ||
| 2. Viewers can possibly witness the total solar eclipse in _____. | ||
[ ] | ||
| A. Liaoning B. Sichuan C. Beijing D. Xinjiang | ||
| 3. When a total solar eclipse happens, _____. | ||
[ ] | ||
| A. the moon goes into the shadow cast by the sun B. the earth stays between the sun and the moon C. the sun temporarily moves into the moon's orbit D. the sun is in a line with the moon and the earth | ||
| 4. Which is the best title for this report? | ||
[ ] | ||
| A. China to witness longest total solar eclipse in 500 years B. The most important total solar eclipse will favor China C. The beginning time of the total solar eclipse is expected D. China has been the best place to witness the solar eclipse |
A
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