.我在回答考试时的问题时非常紧张，以至于我的心里七上八下的。 [

A、 ] When I was answering the exam questions I was so nervous that I could feel butters in my stomach. [

B、 ] I was answering the exam questions I was so nervous that I could feel butterflies in my stomach.

C、 ] When I was answering the exam questions I was such nervous that I could feel butterflies in my stomach. [

D、 ] When I was answering the exam questions I was so nervous that I could feel butterflies in my stomach. [