— _________, this math problem seemed quite simple to me, but when I tried to work it out, I just couldn’t.

— There are always things like this, I think.

A．On one hand

B．In my opinion

C．At first sight

D．On its own

保险监管的前提条件是( )。

A．保险合同是要式合同

B．保险市场失灵的存在

C．保险险种多

D．保险技术性强