问题补充：
His friends were and encouraged him to publish his ideas, but Copernicus was cautious.
A. technical
B. official
C. educated
D. enthusiastic
答案：
A. technical
B. official
C. educated
(答案→)D. enthusiastic
解析： 考查形容词辨析A有技术的B官方的C 教育的D热情的。根据题意 他的朋友很是热情，鼓励他去表达他的想法，但是哥白尼很谨慎。故选 D项。
考点 形容词辨析
