The results show that: 1. A technical phase of the tee, ACE ball remarkably different, average in six.

研究结果表明：1。在发球阶段，ACE球的差异较明显，均数在6个。

youdao

The results show that: 1. A technical phase of the tee, ACE ball remarkably different, average in six.

研究结果表明：1。在发球阶段，ACE球的差异较明显，均数在6个。

youdao