您要查找的是不是：
- polypurine tract PPT
- polypurine tract(PPT) 聚嘌呤区
- He owns a large tract of forest. 他拥有一大片森林。
- He had an infection in the upper respiratory tract. 他上呼吸道感染。
- A line established by sighting in surveying a tract of land. 横断线在测量一块土地时通过目视确定的线
- To the north of the river is an immense wooded tract. 河北面是一大片林地。
- The explorers entered upon a desert tract. 勘探人员进入了一片沙漠地带。
- A sandy tract or dune by the seashore. 沙丘海边的沙地或沙丘
- A tract of territory had been sliced away. 领土被割去了一块。
- He wrote a tract on this subject. 他曾对此写了一篇短文。
- What he saw was a tract of sand. 他看到的就是一片沙地。
- The phylogeny of the amphibian intestinal tract. 两栖动物肠道的演化发展
- Lacking a true body cavity or digestive tract. 无体腔的，无消化道的无真正意义上的体腔的或无消化道的
- A disease of the intestinal tract. 肠病一种肠道疾病
- A tract of water for raising fish is a fish farm. 一片养鱼的水是鱼塘。
- To the north of the river is an immense wood tract. 河北面是一大片林地。
- A medicine for relieving disorders of the chest or respiratory tract. 祛痰药，舒胸药一种用于缓解胸部或呼吸道不适的药物
- The phylogeny of the amphibianintestinal tract. 两栖动物肠道的演化发展。
- Radiography of the urinary tract. 尿路造影术尿路的射线照相术
- A tract of territory had been sliced away . 领土被割去了一块。
