Little attention is on questions of existence of positive solutions for BVP of singular differential equation on measure chains and the relevant papers are few.
测度链上奇异微分方程边值问题正解的存在性，研究的人较少，相应的文献也要少的多。
2
Suppose an advertiser has a RMB30 million budget. If he cannot measure and plan a singular advertising campaign, then he is playing a guessing game.