两互相垂直的主子午线均聚焦在视网膜之后,但聚焦位置前后不同称为()
A.单纯近视散光
B.单纯远视散光
C.复合近视散光
D.复合远视散光
E.混合散光
参考答案:D
— Did you say goodbye to Anna?
— Yes .When I _____ to say goodbye to her, she ______ the piano.
A.go; is playing
B.went; played
C.goes ; was playing
D.went ; was playing
从信令流程的先后顺序来看,以下呼叫建立失败原因的先后顺序正确的是()。
A、MSC拒绝→呼叫早释→等待移动台响应超时→捕获移动台反向业务帧前导失败
B、捕获移动台反向业务帧前导失败→MSC拒绝→等待移动台响应超时→呼叫早释
C、MSC拒绝→捕获移动台反向业务帧前导失败→呼叫早释→等待移动台响应超时
D、MSC拒绝→呼叫早释→捕获移动台反向业务帧前导失败→等待移动台响应超时