certificate of approval是什么意思啊?

certificate of approval是什么意思啊? certificate of conformity是什么意思? certificate of enrollment是什么意思 certificate of honor是什么意思 certificate of conformity是什么意思 certificate of completion是什么意思 “certificate of conformity”是什么意思? acknowledgement of certificate是什么意思 certificate of attendance是什么意思 certificate of registration是什么意思 certificate of participation是什么意思 certificate of guarantee是什么意思