Software quality assurance is now an emerging sub - discipline of (36) . As Buckly and oston point out, (37) software quality assurance is likely to lead to an ultimate (38) of software costs. However, the major hurdle in the path of software management in this area is the lack of usable software (39) . The development of accepted and generally applicable standards should be one of the principal goals of (40) in software engineering.

A．balance

B．increment

C．production

D．reduction

(10分)如图所示，在倾角为37°的光滑斜面上水平放置一条长为0.2 m的直导线PQ，两端以很软的导线通入5 A的电流．当加一个竖直向上的B＝0.6 T的匀强磁场时，PQ恰好平衡，则导线PQ的重力为多少？(sin 37°＝0.6)