Question

_____ORBIS doctor who got here yesterday needed _______ X-ray machine to
examine his patients.

A．The; a

B．The; an

C．An; a

D．An; an

Answer 1

B

此题考查冠词的用法，the是定冠词，表示特指；a/an是不定冠词，表示泛指。a用在辅音音素开头的单词之前，an 用在元音音素开头的单词之前。