急性特发性血小板减少性紫癜的临床特点()
A.不能自行缓解
B.儿童多见
C.不可能出现内脏出血
D.多有病毒感染史
E.血小板明显减少
参考答案:B, D, E
If the sum of a 4-digit natural number and 17,the difference between it and 72 are all square numbers ,then the 4-digit natural number is( )
(英汉小词典:4-digit natural number四位自然数;difference差;square numbers完全平方数)