转氨酶正常但HBVDNA阳性者，建议几个月进行一次AFP和B超检查？（）
A、3个月
B、6个月
C、1个月
D、1年
参考答案：A
—Could you tell me ____________________?
—I don’t know. It seemed to be unimaginable.
A．why “Gangnam style” is known to all in China
B．when was “Gangnam style” so popular in China
C．where “Gangnam style” is popular
D．how was “Gangnam style” well-known in China
文章题目为“旅鼠之谜”，北极旅鼠的奥秘有哪些？
答：______________________________________________
