这几个英语句子填什么介词

这几个英语句子填什么介词
1.the shops use many methods to compete —— customers
2.in my opinion,the mistakes arose —— your carelessness
3.there is still some doubt —— the safety of the newly designed plane
4.some products are not —— high quality in the store
5.there is a long queue before the entrance —— the museum