集合{x∈N^*|x＜5}的用列举法表示为（　　）

A．{0，1，2，3，4}

B．{1，2，3，4}

C．{0，1，2，3，4，5}

D．{1，2，3，4，5}

He ＿＿articles for our wall-newspaper these three years, and he ＿＿about forty articles.

A．has been writing； has written

B．has been writing； wrote

C．is writing； has been writing

D．has written； has written