you must be fifty,___?

you must be fifty,___? you must be ___!(kid) Fifty dollars for such a T-shirt!You ( ) be joking A.must B. you must be careful when you ___ with fireworks you must be joking改为同义句 you ___ ___ ___! You must ___(be) careful____(红绿灯处） You must ___(be) careful (在红绿灯处） ①she must be fifty（对划线部分提问）划线的是fifty We must ___(be) careful. But you must be ___ in it and keep the room ___ You must be careful to drive the car.改为同义句___ ___ ___to driv Is it bag ___ ,Tom.（you） No,it isn't___ .(I) It must be ___