词法分析器用于识别（）
A.字符串
B.语句
C.单词
D.标识符
参考答案：C
枕左前位胎头进入骨盆入口时衔接的径线是
A．枕颏径B．枕额径C．双顶径D．双颞径E．枕下前囟径
－ ______does your brother watch TV every day?
－For half an hour.
A．How many
B．How often
C． How much
D． How long
