下列各句中，不含通假字的一项是（　　）

It was with great joy _______ he received the news _______ his lost son would soon return home.

I took mathematics and physics because I think that ________ very important for me to make further research in this field.

Why do you want a new job ____ you’ve got such a good one already?

________atmospheric haze(雾霾天气) or smog will continue makes the public worried