题目

 Now, the world’s focus is all on_______it is that the global economy will come back to normal. A. why   B. what  C. where   D.when 答案：D下面计算正确的是（　　）A．3a2?2a3=6a6B．3x2?4x2=12x2C．2a3?4a5=8a15D．3a2?5a3=15a5