—Has Mary been back?—Not yet.She will come back the evening of June .A. at firstB. to thi

问题补充：

—Has Mary been back?

—Not yet.She will come back the evening of June .

A. at,first

B. to,thirtieth

C. on,the twelfth

D. on,the nineteen

答案：

A. at,first

B. to,thirtieth

(答案→)C. on,the twelfth

D. on,the nineteen

解析：考查时间介词和序数词。“玛丽回来了吗？”“还没。她一月二十晚上回来。”指具体的一天或上下午、晚上用介词on，排除A、B；D项的日期没有用序数词形式。故选C。