on + 星期/weekends 的用法 — 英语词汇题
题目
Mike 的周末安排表如下：Saturday—play basketball, Sunday—go swimming, Friday—have an art class。请根据安排，用介词 on 和正确的星期单词补全句子（每空一词，首字母已给出）：
1. He plays basketball o____ S_______.
2. He goes swimming o____ S______.
3. He has an art class o____ F______.
4. He is busy o____ w________ (在周末).