日语
韩语
法语
德语
西班牙语
意大利语
阿拉伯语
葡萄牙语
越南语
俄语
芬兰语
泰语
从下列各题所给的A、B、C、D四个选项中，选择可以填入空白处的最佳选项。
（ ）19．-Is this ______ classroom?
-No, it’s theirs.
A. we B. us C. our D. ours
（ ）20．- What did you do ______ Sunday morning?
-We just stayed at home and watched TV.
A. on B. in C. at D. for
（ ）21．My parents ______ both teachers. They teach in the same school
（ ）19．-Is this ______ classroom?
-No, it’s theirs.
A. we B. us C. our D. ours
（ ）20．- What did you do ______ Sunday morning?
-We just stayed at home and watched TV.
A. on B. in C. at D. for
（ ）21．My parents ______ both teachers. They teach in the same school
