当胃和结肠内气体较多时,检查胰腺的体位采用:
A.仰卧位
B.侧卧位
C.坐位或半坐位
D.俯卧位
参考答案:C
In April , thousands of holidaymakers remained ______ abroad due to the volcanic ash cloud.
A.sticking
B.stuck
C.to be stuck
D.to have stuck
简述海蓝宝石的主要性质。