用例的扩展关系在UML图中是虚线箭头，其上标注（ ）。 A: <<include>> B: <<extend>> C: <<class>> D: <<object >>

extend

How many beats can the pause extend? A: 1 beat B: 2 beats C: Extend appropriately according to the piece style D: Extend the total duration of this measure by half

确保两个活塞伸出长。 A: Make sure that the two pistons extend equally. B: Ensure the two pistons extend evenly. C: Ensure the two pistons extend uniformly.

Generally speaking, when two people meet, _______________________. A: the one with higher rank or authority will first extend his or her hand B: the one with lower rank or authority will first extend his or her hand C: They extend their hands at the same time

Please extend the L/C for ten days.

They have a downstairs phone and an ________ in each of the bedrooms. (extend)

比较化合物乙酸（Ⅰ）、乙醇（Ⅱ）、苯酚（Ⅲ）、碳酸（Ⅳ）的酸性大小（ ） A: Ⅰ>Ⅲ>Ⅱ>Ⅳ B: Ⅰ>Ⅳ>Ⅲ>Ⅱ C: Ⅰ>Ⅱ>Ⅳ>Ⅲ D: Ⅰ>Ⅲ>Ⅳ>Ⅱ

化合物①对甲基苯酚,②对甲氧基苯酚,③对三氟甲基苯酚,④对溴苯酚,⑤苯酚酸性强弱顺序正确的是( ) A: ③>④>>⑤>②>① B: ④>③>>⑤>①>② C: ③>④>>⑤>①>② D: ②>①>⑤>④>③

比较化合物①乙酸、②乙醚、③苯酚、④碳酸的酸性大小是:() A: ①>③>②>④ B: ①>②>④>③ C: ①>④>③>② D: ①>③>④>②