— I wonder _______.
— I'm afraid we'll be late.
A:how we can be on time
B:if we arrive at the meeting on time
C:why we get to school late
D:if we will arrive at the meeting on time
如图是某生态系统食物网示意图.请分析回答下列问题:
决定人的有耳垂与无耳垂性状的是( )