下载APP
参考答案：
参考解析：
刷刷题刷刷变学霸
举一反三
【单选题】在我国历史上,创造和改进了简仪、仰仪、高表等观测天象的仪器,主持编制了《授时历》将一个回3年的天数精确到365.2425 天的数学家、天文学家是( )
A.
张衡
B.
祖冲之
C.
郭守敬
D.
徐光启
【单选题】How much sleep does a person need (31) the physiological bases of the need for sleep remain conjectural (猜想), rendering conclusive answers to this question impossible, much evidence has been gathered...
A.
unless
B.
however
C.
although
D.
even if
【单选题】How much sleep does a person need?【B1】the physiological bases of the need for sleep remain conjectural(猜想), rendering conclusive answers to this question impossible, much evidence has been gathered on...
A.
As
B.
Despite
C.
While
D.
Whether
时，
时，
时，
时，