It’s really exciting experience to go on a trip into space. A an / B an the C the /

问题补充：

It’s really exciting experience to go on a trip into space.

A an, / B an , the C the , / D the , the

答案：

解析：考察冠词。第一空的experience是可数名词经历，前面可以有不定代词；第二空的space指太空，是一个专有名词，单独使用。故A正确。