视杯与视柄（）。
A.与端脑相连
B.与间脑相连
C.与中脑相连
D.与后脑相连
参考答案：B
蜜蜂在找到食物后，会在空中跳“8”字摆尾舞招引同伴前去采蜜，这种现象在生物学上称为 [ ]
A．合作
B．寄生
C．捕食
D．竞争
The number of people invited ______ fifty, but a number of them ______ absent(缺席) for different reasons.
A．were; was
B．was; was
C．was; were
D．were; were
