The Japanese are good at playing basketball 这个句子是对的吗

The Japanese are good at playing basketball 这个句子是对的吗 Are you good at playing basketball的答句是什么? 这个英语句子是对的吗i saw them were playing basketball on the groud.是正 Are you good at playing basketball?同义句转换 They are good at playing basketball.（转为疑问句） We are playing basketball at school(对at school提问) You are good at playing the piano.的答句 He is good at playing basketball的同义句 He is good at playing basketball. they are playing basketball ( on the field)对括号提问. He is good at playing basketball 如果不不加playing可以吗? I am good at playing basketball. 这个英文属于什么时态,