at sb’s invitation;on(or upon)invitation 中國代表團~出席大會,感到榮幸和愉快。The Chinese Delegation is honored (or privileged) and pleased (or delighted) to be invited to the Conference/~出席國宴be invited to the state banquet;attend the state banquet upon invitation/~來中國訪問come to visit China upon invitation/~派代表團參加國慶活動send a delegation to attend the national day celebrations at the invitation (of the Chinese Government)