人工合成的植物激素类似物常用于生产实践。某课题组研究了激素类似物甲和激素类似物乙对微型月季生根和侧芽生长的影响，请回答下列问题：
已知甲为生长素类似物，图2为其X、Y和Z三种浓度下对微型月季茎段侧芽生长的影响，则：①X浓度的甲对微型月季茎段侧芽生长具有（）作用。②X浓度、Y浓度和Z浓度之间大小的关系是（）。
参考答案：①抑制；②X>Y，X>Z；Y与Z之间大小关系不确定
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| World No.2 tennis 1 Elena Anodic from Serbia (塞尔维亚) has won her second title of the year. She became champion of the China Open 2 September 28. Jankovic first practiced tennis when she was nine years old. After six months Jankovic played her first match. It was the 3 championship for kids up to 10 years old. She came to the semi-finals (半决赛). When she was 11, she won a national championship for girls up to 12 years old. 4 continue her career, Jelena 5 Serbia and went to the United States. At that time, she 6 speak any English. And her family did not come with her. It was a hard time."I did not know what I needed 7 when I was going to school. I could not do my homework. When you have a 8 , there is nobody to help you. So, you learn it the hard way," Jelena said. However, it was a good 9 experience for Jelena. "It makes me 10 independent (独立的) and stronger as a person. I know 11 everything by myself, so I don't have to 12 my parents 13 somebody else to do it for me," she said. In the US, Jelena received better conditions for practice and 14 of her game. In 2000, she became a professional (职业选手) and has been shining on the tennis court 15 . | ||||
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