html cells merge

<Table border = ". 1" style = {{margin: 200 is}}> 

<tbody> 

<TR> 

    <TH colspan = "2"> is a placeholder I </ TH> 

    <TH colspan = "2"> I placeholder </ TH> 

</ TR> 

<TR> 

    <TH rowspan = "2"> is a placeholder I </ TH> 

    <TH> is a placeholder I </ TH> 

    <TH> I is a placeholder Fu </ TH> 

    <TH> I is a placeholder </ TH> 

</ TR> 

<TR> 

    <TH> I is a placeholder </ TH> 

    <TH> I is a placeholder </ TH> 

    <TH > I placeholder </ TH> 

</ TR> 

</ tbody> 

        </ Table>