OG-58求助！
Neither a rising standard of living nor balanced trade,by itself,establishes a country's ability to compete in the international marketplace.Both are required simultaneously since standards of living can rise because of growing trade deficits and trade can be balanced by means of a decline in cuontry's standards of living.
If the facts stated in the passage above are true,a proper test of a country'a ability to be competitive is its ability to
A. balance its trade while its standard of living rises
B.blance its trade while its standard of living falls
C.increase trade deficits while its standard of living rises
D.decrease trade deficits while its standard of living falls
E.keep its standard of living contant while trade deficits rise
（A）
答案我明白, 可是题目里面的那个
since standards of living can rise because of growing trade deficits and trade can be balanced by means of a decline in cuontry's standards of living.
这又是怎么回师呢?这么说对? | 
