问题
选择题
Although everything seems to have been taken into consideration, ________ accident can happen when the astronauts walk in ________ space.
A．/; the
B．an; the
C．the; the
D．an; /
答案
答案：D
考查冠词。第一空填不定冠词表泛指，第二空space“太空”前不加冠词，故选D项。