What may be the oldest fossil footprint ye

问题单项选择题

What may be the oldest fossil footprint yet found was discovered in June 1968 by William J. Meister, a non-professional fossil collector.

A．a part-time

B．a spare-time

C．an untrained

D．an amateur

答案

参考答案：D

解析：形容词辨析。A．a part-time部分时间的，非全日的，兼职、兼任的；B．a spare-time；C．an untrained未经训练的；D．an amateur业余爱好者；而non-professional非专业的，非职业的，因此D是答案。