a fitness center前面用at 还是on能用on吗？为什么？

a fitness center前面用at 还是on能用on吗？为什么？ fitness center look sharo fitness center fitness and wellness center fitness center啥意思 fitness center的意思有四个选项：A.商务中心 B.健身中心 C.购物中心 D.医疗中心如题 Exercising can be f_____.Friends can exercise together at a fitness center.一道首字母填空 如题 Exercising can be fun.Friends can exercise together at a fitness center.Or,they can play sports together. go on a fitness camp fitness center是什么意思working out after i over the dance at the fitness center,in the elevator ,an old man happyly share a poem with me!it is call the meaning of living 英语翻译fitness center 与 health center有何区别 a shopping center是什么意思 英语翻译Summary of the United States speak a different origin from the generation,development and change formed.Modern society,people to have healthy and has used health,fitness and health center characteristics of the overall effect of a means o 英语翻译A fitness center purchased a number of exercise machines:4 costing $1700 each,8 costing $1300 each,and x costing $1200 each,where x is a positive odd integer.If the median price for all the exercise machined purchased by the fitness cente they suggested that preschool children go to a childcare center or to a babysitter.前面有了go toor后面为什么还用to cough 有一个句子：Marry is surprised to find Wilson at the fitness center because Wilson is a cough potato.请问句子中的cough 还有最好还附上整句的翻译. 请问merchantability or fitness for a particular purpose 怎么译