It"s such a ______ concept that it seems to have been around for all time, but packaged sliced bread has only been available since the late 1920s.

A、 radical
B、 fresh
C、 primitive
D、 hollow
E、 meaningless

【正确答案】 C

【答案解析】The clue here is "it seems to have been around for all time." That would not describe something radical (choice A) or fresh (choice B), but it could describe something primitive (choice C).