Помогите с английским, перевести в passive voice

Question

Rewrite the sentence.Use the passive voice (Перепишите предложения. Использовав пассивную конструкцию) (Перепишите предложения. Использование пассивной конструкции) 
1)Every bode aiways laughs at his jokes 
2)They have already sent for the doctor 
3)People often refer to this book 
4)We waited for Kate for ten mintes yesterday

Ира Берегова · Accepted Answer

His jokes are always laught at. 
The doctor is already sent for. 
This book is often referred to. 
Yesterday Kate was waited for for ten minutes.

Ирина Гизатова · Answer

Я думаю, что так: 
1.) His jokes are always laughed at by everybody. 
2.) The doctor has already been sent for (by them). 
3.) This book is often refered to (by people). 
4.) Kate was waited for ten minutes yesterday.