发生未定义的控制序列错误。我应该在这里使用哪个包？或者任何其他错误？

Question

\multirow{2}[2]{*}{1.1} & \multicolumn{1}{c|}{\multirow{2}[2]{*}{Q>10\newline{}Good to very good}} & \multicolumn{1}{c|}{\multirow{2}[2]{*}{I}} & \multicolumn{2}{c|}{\multirow{2}[2]{*}{50}} & \multicolumn{1}{c|}{\multirow{2}[2]{*}{25mm $\straightphi$ spot rockbolts 2.5m long as required}} & \multicolumn{1}{c|}{\multirow{2}[2]{*}{-}} & \multirow{2}[2]{*}{} \bigstrut[t]\\
      &       &       & \multicolumn{2}{c|}{} &       &       &  \bigstrut[b]\\
\hline