| 1. | The incidence of gallstones increases progressively with age .
胆石症的发病率随年龄而逐渐增高。 |
| 2. | The incidence of this disease has dropped considerably in the past few years .
近几年这种病的发病率大大降低了。 |
| 3. | This practice reduces the incidence of bare wood on trees of many cultivars .
这个措施对许多品种的植株说来，能减少光秃枝的出现。 |
| 4. | The ratio of cross-links to branches may be varied by altering the incidence of chain transfer .
通过改变引入的链转剂就可以改变交联与支链的比例。 |
| 5. | For any given distribution, the lower the average income level, the greater the incidence of poverty .
对任何既定的分配来说，平均收入水平越低，贫困的范围就越大。 |
| 6. | An estimate of the risks in terms which may be related to the incidence of genetic disorders in man will also be given .
与人类遗传性疾病的发生有关的危害的估计也将作出。 |
| 7. | The distinction is not analytically useful as it is not informative about the incidence of the tax .
这个区别在分析中并无用处，因为它对于税收的归宿问题不能提供更多的资料。 |
| 8. | Improvements in drainage and fertility levels are in themselves methods of reducing the incidence of some of these weeds .
改进排水和肥力水平本身就是减少某些杂草生长的方法。 |
| 9. | There is an association between airquality levels and the incidence of pulmonary disease in the world's cities .
在世界大城市中，空气污染水平和肺病发病次数之间存在着某种关系。 |
| 10. | The controls over the incidence of growth are exercised by a balance of factors which promote and which antagonize .
对于生长范围的控制，是靠促进因子和拮抗因子间的平衡来达到的。 |
