We only had $100 and that was ________ to buy a new computer.[    ]

A. nowhere near enough  

B. near enough nowhere

C. enough near nowhere  

D. near nowhere enough

流I=2.0A，方向向左，导体棒受到的安培力大小为4×10^-3N求：

（1）安培力的方向如何？

（2）磁感应强度大小。

（3）若导体棒中电流大小为3A，则导体棒所受安培力多大？