单项选择题从形体体块的四个正角度观察每段体块都类似于竖直的橄榄核形,从其最粗的部位向两端逐渐缩窄,而窄的部位就是我们所说的形体体块衔接出的活动关节的位置。( )A.对B.错
单项选择题The majority of vocabulary acquisition occurs A、independently by learners studying word lists B、incidentally through oral and written exposure C、intentionally through formal classroom instructio