在（）上，居民向生产单位出售他们的劳动力和其他生产要素资源，并从对方取得要素收入——

Only when I read this story for a second time         to appreciate its beauty. [ ]

A. did I begin    

B. that I began  

C. I began    

D. had I began

表观密度小，吸声绝热性能好，可作为吸声或绝热材料使用的板材是( )。

A．五合板

B．硬质纤维板

C．软质纤维板

D．刨花板

短文填空

To make sure that there was enough   78  for his sister’s wedding meal（婚宴）， Ma missed four school days. He   79  the time carrying water from a lake, 30 miles away from his home. “How I wish I could live   80  a river,” said Ma.

This is the dream of many in northern China.   81  it has the world’s third largest quantity（数量）of water, China is    82  of the 13 thirstiest(最干旱的) countries.

The areas that are in most need of water are western and northern China, where there is   83  rain. These areas have just six percent of the country’s total water, but that water has to feed one third of Chinese people. Much of the water comes from underground. But using much underground water has made the ground sink（下沉）in some places.

Things are getting   84  worse because people are wasting water. Half of the water that farmers use for crops goes to waste. Factories use more water   85  they need and they put dirty water into rivers and lakes. The less water there is, the more worried people will be. How can we use water in a smart way? It’s a question for you to think about on World Water Day, Mar 22.

根据病理组织形态子宫颈炎可分为（）、（）、（）、（）和（）几种类型。

运用所学知识分析下列命题：

时空与物质运动是形式与内容的关系。