Usually I sleep for eight or nine hours a night.中为什么要用介词for而不用介词about?

I usually sleep when it‘s raining对sleep提问 Usually I sleep for eight or nine hours a night.中为什么要用介词for而不用介词about? I sleep for nine hours every night i sleep for eight hours.中的for必须用吗? 初二英语对话填空what ( ) do you ( ) play on weekends?I usually play golf.how ( ) do you usually sleep?I ( ) to sleep 7 to 8 hours every day I usually look for cookies 中文是什么? i usually sleep eight hours every night 就“eight”一词进行提问_____ _____ _____ do you usually sleep every night? I usually sleep with the window open（）it is very cold.Aunless Bas Cif open,i ,with ,windows ,the,sleep ,usually (连词成句） I usually sleep when it's raining对划线部分提问 sleep ,hours,about,usually,ten,I连词成句,拜托,马上要 I usually (sleep)when it is raining?对括号里的单词提问 Usually I sleep （ ） eight or nine hours a night.这题如果出现了类似的填空题,只有一个空,且只能填介词,一空一词的话,是不是都填for? I will make good food,good sleep,good waiting for sleep、eight、for、day、a、i、hours怎么写成句子 I never sleep for less than nine hours.中文是什么? After lunch,I sleep for an hour ( ) (one) I sleep eight hours for every night. 和 I sleep for eight hours every night.哪个对?