[单项选择]按照国际公认的警戒线，一国外债结构是否合理，关键看短期外债余额在全部外债余额中的比重。如果低于( )，则表明外债结构合理，反之则预示着存在外债风险。
A. 10%
B. 20%
C. 30%
D. 40%

Good sense is the most equitably distributed thing in the world, for each man considers himself so well provided with it that even those who are most difficult to{{U}} (47) {{/U}}in everything else do not usually wish to have mom of it than they have already. It is not likely that everyone is{{U}} (48) {{/U}}in this. It shows, rather, that the ability to judge rightly and separate the true from the false, which is essentially what is called good sense or{{U}} (49) {{/U}}, is by nature equal in all men; end thus that our opinions differ not because some men are better{{U}} (50) {{/U}}with reason than others, but only because we direct our thoughts along different paths, and do not consider the same things. For it is not enough to have a good mind; what is most important is to{{U}} (51) {{/U}}it rightly.
The greatest souls are capable of the greatest vices; and those who walk very slowly can{{U}} (52) {{/U}}much further, if they a