均衡风缸的容积为（）升。
参考答案：13.5
The split between humans and living apes is thought by some scholars ____ 15 to 20 million years ago.[ ]
A. to occur
B. occurring
C. to have occurred
D. having occurred
陈某（13岁）父母离异，由于父母忙于工作，陈某在家自己居住，根据我国法律不得让不满（）的未成年人脱离监护单独居住。
A、十四周岁
B、十五周岁
C、十六周岁
D、十八周岁
and living apes is thought by some scholars ____ 15 to 20 million years ago.[ ]