在MRI图像上下列哪种肿瘤看不见化学位移伪影()
A．皮样囊肿
B．脂肪瘤
C．畸胎瘤
D．神经鞘瘤
E．胆脂瘤
参考答案：D
样本数据3，2，5，a，4的平均数是3，则a= ．
—Is the film interesting?
—I thought it would be. But ______, it’s very boring.
A．in all
B．in fact
C．in addition
D．in future
