数学的第一次危机是由于出现了()而造成的。
参考答案:
无理数(或√2)
We are going for a picnic tomorrow. I'll call Wendy to make sure ______. [ ]
A. why to start
B. when to start
C. what to start
D. which to start
分泌混合毒素的毒蛇为
A、金环蛇
B、海蛇
C、眼镜蛇
D、五步蛇