A：
B：
C：
D：
Hello! Welcome to my show(欢迎参观我的展览). They're my animals. Look! The lion has got a blue shirt. The tiger has got a red hat. The monkey has got a yellow skirt. The panda has got a green T-shirt. Has the elephant got a brown sweater? No, he hasn't. He has got an orange sweater. That's very funny.
A. B. C. D. E.
最先证明地球是个球体的事件是（ ）
（Ⅰ）记甲恰好击中目标2次的概率；
（Ⅱ）求乙至少击中目标2次的概率；
（Ⅲ）求乙恰好比甲多击中目标2次的概率；
是虚数单位，若
，则
的值是 （ ）
B. 
C. 
D. 
E. 
DNA黏性末端可以互补配对的是 （ ）
学