There are forty students in Tom's class. of them comes from Beijing.
A:None
B:Both
C:Neither
D:All
用演绎推理证明“y=tanx是周期函数”时,大前提为____
填上适当的量词。
一____风景 一____树 一____树坑 一____小猫
已知:如图,AD、BE分别是△ABC的中线和角平分线,AD⊥BE,AD=BE=6,则AC的长等于____ .