视神经的血供来源于
A．眼动脉
B．大脑前动脉
C．大脑后动脉
D．脉络膜前动脉
E．前交通动脉
参考答案：A
A new survey released by Yale University finds that Americans trust scientists most when ______ comes to information on climate change.
A．that
B．it
C．this
D．there
社会保障的目的是保障______。
A．生活幸福B．人民富裕C．社会安定D．生活水平
