I don't know what to say.的同义句是什么?He asked the policeman where to go.的同义句是什么?We want to know when we will climb Mount Tai

I don't know what to say.的同义句是什么?He asked the policeman where to go.的同义句是什么?We want to know when we will climb Mount Tai.的同义句是什么?I can't choose which book to buy.的同义句是什么?同义句句型为I don't know___________________He aksed the policeman__________________________We want to know________________________I can't choose which book＿＿＿＿＿＿＿＿＿＿＿＿＿．