I don't know _____ I am free this afternoon.A whether B if 选哪个?为什么

I don't know. I don't know whom I should ask(改为同义句）I don't know whom _____ _____. 改为同义句：I don’t know what I should buy her.I don't know _____ _____ buy her. I don't know what we will do next.(改为同义句)I don't know _____ _____ _____ next. “i don't know you know i don't know 英语翻译I don't know _____ ______ _____next. I don't know what _____（eat） for lunch I don't know which sweater _____(choose) I don,t know which one _____ （choose) I don't know which watch _____(choose). I don't know why he _____(like) elephants. What would happen if I don't know anyone?=_____ _____ I don't know anyone? What does he like wearing I don't know.(合为一句) I don't know _____ _____ ______. I don't know what shuold I do 的同义句是什么?I don't know _____ _______ _________ I do not know what to do.同义句子I don't know_______ ______ _____ _____. sorry,I don't know. i don`t know much I don't really know.