A:to buy which one
B:buy which one
C:which one to buy
D:which one should I buy
关于光纤通信,下列说法错误的是( )
①树立安全意识、自我保护意识
②学会运用法律维护自己的权益
③了解寻求法律帮助的途径和方法
④面对违法犯罪,要见义勇为,敢于牺牲