间接一般疑问句 do you think that 和 do you think if 的区别

间接一般疑问句 do you think that 和 do you think if 的区别
例如：
Do you think that this kind of accident is acceptable?
Do you think if this kind of accident is acceptable?
表达的意思都一样么,表达方式都正确么,请高人指教,
上面两个句子算是间接一般疑问句么，另外例如：I want to know if this kind of accident is acceptable.只有这样的句子才是间接一般疑问句吗？