I have a soccer ball. ______ play soccer. [ ]
A. Let
B. Do
C. Let's
答案：C
— Imagine you are outside when _____ earthquake comes. What should you do?
— Go to _____ open space away from buildings or trees. [ ]
A. the; the
B. the; an
C. an; the
D. an; an
指出下列摄片技术中，不正确的是()
A．柯氏位可显示筛窦的前后两组影
B．眼眶肿物应选择柯氏位、瑞氏位和眶缘切线位
C．上颌窦肿瘤取瓦特位外，还应摄取颅底减角位(半轴位)
D．瓦特位，两侧密度不一致(非病变所致)的原因，主要是中心线偏斜或滤线栅侧向倾斜造成的切割效应
E．眶下裂摄片采用取头颅后前正位，中心线向头侧倾斜20°
