被试间设计克服个体差异的方法,有()和()。
参考答案:匹配;随机分组
GSM-R系统采用()工作频段。
A.600MHZ
B.700MHZ
C.900MHZ
D.800MHZ
( ) 1. Hi, what's your name?( ) 2. Thank you.( ) 3. Where is Sandy, my brother?( ) 4. What's he doing?( ) 5. How are you?