用于测量眼球轴长,最准确的是
A.超声生物显微镜(UB
B.电子计算机体层扫描(C
C.彩色多普勒成像(CD
D.B型超声扫描
E.A型超声扫描
参考答案:E
You have to speak slowly in order to ____.
A.make you understood
B.make youself understood
C.make them understand
D.make themselves understand
我国发明专利的保护期为( )年,期限自专利申请日算起。
A.10 B.20 C.30 D.50