①秋季里,____。
②____是大事。
③春季里,____。
④____,我真开心。
We felt disappointed when we found the journey was not as nice as we had e____.
如图曲线b表示在最适温度、最适pH条件下,反应物浓度与酶促反应速率的关系.据图分析正确的是( )