Do you know the difference water and oil?When you ____ ,what will be on the top?A.mix it up B mix up it C mix them up ,水和油都是不可数名词,应该用it 来代替,为什么答案是选C啊,

Do you know the way? do you know the mean do you know the time lunchDo you know the time_____lunch? Do you know the to the question? Do you know the girl i__red? Do you know the girl ___ red what do you know about the Do you know the girl over Do you know the girl for yellow? Do you know the pizza girl? Do you know () the rain come from? Do you know the girl（ ） glasses The game came over do you know Do you know the boy ()(name) David Do you know what c___ the fire Do you know the question n___ three? do you know the man__________peter smith(name) Do you know what the answer is?