Yet it turns out that millions of nets were already in use in the part of Kenya where the field trial took place, so their value was known.
当然，已经有数以百万计的蚊帐在肯尼亚的试验区被使用，因此其价值是看得到的。
2
While determining the number of connections needed is not an exact science, through trial and error and application monitoring the best possible value can be found.