9. Ronald seems to know all kinds of serve techniques-the backhand topspin and backspin serves, the forehand topspin and backspin serves, and the high toss serves.

• 所有的发球技巧，罗纳德似乎都懂-----反手上旋球和下旋球、正手上旋球和下旋球以及高抛球。收藏指正