If you are relocating to Raleigh, North Carolina or the Research Triangle Park area, this information may help you find the best dentist to provide the level of care most appropriate for you and your family. Despite the negative effects that virtual reality can bring to video gamers, there are positive uses for the technology. For example, the Oculus Rift could be used to train pilots in crash procedure without the danger of actually crashing a plane. This type of simulation could also be used for law enforcement or other first response workers. Athletes could use virtual reality for realistic training programs outside of team practices. Finally, virtual reality can allow people to experience activities that they would not be able to otherwise. Since 2012, the hospitalized delivery rate in China was over 99%. 28 Therefore, the hospital-based data is very close to population data for maternal complications. The sampled urban districts and rural counties in NMNMSS are based on the surveillance sites in NMCHSS, a nationally representative surveillance system approved by the National Health. Commission of China. 20,28 However, the major problem is the health facility selection criteria in the NMNMSS. In order to ensure that a sufficient number of maternal near miss cases and maternal deaths are monitored within the hospital, large hospitals are oversampled. In particular, some hospitals in rural counties have not been sampled because of the small number of annual delivery. One of the feasible solutions to oversampling large hospitals is to weight the data against the probability of each individual to be collected in the NMNMSS in each region and rural or urban area according to the population census. Although the proportion of population in NMCHSS and whole country are very close in each stratification, the proportions of population in NMNMSS between rural and urban areas within each region are much different from those in the whole country. Therefore, we need to use the weights (see Table 1 ) to adjust the crude data. We have done this in some previous studies without any doubt from peer-review. 18,19 A more precise approach is to calculate the weights and adjust the crude data based on the number of live births per year in each urban district or rural country. Another possible way is to adjust the crude data based on the ratio of the number of live births between the whole country and the NMNNSS stratified by maternal age group. This approach is based on the hypothesis that there is a strong association between maternal age and pregnancy complications. However, we have no way to access these two data sources in the past. Actually this is part of the theory. Most people who claim to believe in Evolution don’t even realize it. I’m sorry I cannot do the homework for you, but you should look into it.