胰头癌的最常见首发临床表现是（）
A.黄恒
B.稀便
C.贫血
D.上腹隐痛
E.皮肤瘙痒
参考答案：D
解析：腹痛为多数患者的首发症状。
看图判断正(√)误(×)。
( ) 1. We have a TV room.
( ) 2. We don't have a music room.
( ) 3. The art room is on the first floor.
( ) 4. The washroom is on the first floor.
( ) 5. The canteen is on the first floor, too.
( ) 6. We don't have a gym.
同一床速扫同一范围，螺距等于2与螺距等于1时相比，病人承受剂量的关系是()
A．螺距2和螺距1相等
B．螺距2是螺距1的1.5倍
C．螺距2是螺距1的2倍
D．螺距2是螺距1的0.75倍
E．螺距1是螺距2的2倍
