【2013内蒙古呼和浩特】He invited some classmates to come to his party,but _______ came.
_______, when Marx was already _______, he found it was important to study the situation in Russia, so he began to learn Russian.
It is well known _____ all people that Beijing is known _______ the capital of China.
His aunt wants to get him _______ the radio, but he has had it _______ already.
There is still some cake _______ in the fridge. You don’t need to buy any.
I don’t doubt _______ he can finish the task, but I doubt _______ he is willing to do it.