When we put the suggestion to him he thought highly of it and was about its immediate ap

问题补充：

When we put the suggestion to him, he thought highly of it and was about its immediate application.

A. curious

B. content

C. cautious

D. enthusiastic

答案：

A. curious

B. content

C. cautious

(答案→)D. enthusiastic

解析：形容词辨析。Be curious about…对…好奇；be content with对…满意；be cautious about对…谨慎；be enthusiastic about热衷于，对…充满热情；句意：当我们向他提出建议的时候，他对我们的建议高度评价，对于建议的立刻运用充满了热情。