借助语法总结表自查语法错误 — 英语选择题

Lily 用本单元《Grammar Summary》自查日记，表中提示：现在进行时用 be + V-ing，be 动词随主语变化；表 plan 类双写尾字母再加 -ing。请按表自查，选出有错误的一句。A. She is running in the park now. B. Look! The boys is playing basketball. C. I am doing my homework now. D. He is swimming in the river.