[单项选择]男孩，1岁。低热、盗汗1个月，轻咳10天。胸片呈双极影，诊断为原发复合征。不符合活动性肺结核的是（）
A. 有发热及其他结核中毒症状
B. 结核菌素试验硬结直径≥15mm
C. 胃液找到抗酸杆菌
D. 红细胞沉降率增快，而无其他原因解释
E. 胸部X线片示渗出性改变

When there is blood in the water, it is only natural that dorsal fins swirl around excitedly. Now that America’s housing market is ailing, predators have their sights on the country’s credit-card market. Analysts at Goldman Sachs reckon that credit-card losses could reach $ 99 billion if contagion spreads from subprime mortgages to other forms of consumer credit. Signs of strain are clearly visible. There are rises in both the charge-off and delinquency rates, which measure the share of balances that are uncollectable or more than 30 days late respectively. HSBC announced last month that it had taken a $1.4 billion charge in its American consumer-finance business, partly because of weakness among card borrowers.
It is too early to panic, though. Charge-offs and delinquencies are still low. According to Moody’s, a rating agency, the third-quarter delinquency rate of 3.89% was almost a full percentage point below the historical average. The deterioration i
A. To remind people of the potential danger
B. To attract the readers’ attention by presenting an interesting phenomenon
C. To show that the issue is rather serious, just as a dorsal fin is approaching
D. To present some fresh air at the beginning, thus making the narration more vivid