患者男性，9岁，常年咳嗽，无其他自觉症状，X线检查如图所示，最可能的诊断是()
A．结核球
B．原发性肺癌
C．炎性假瘤
D．纵隔肿瘤
参考答案：C
Tom's aunt wants to know ________ he has been up to so far, therefore, she decided to send
him an e-mail. [ ]
A. which
B. why
C. what
D. how
DL451-91规约规定通道发码规则，（）先送，字节内（）位先送。
A.低、低
B.高、低
C.低、高
D.高、高
