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参考答案：
参考解析：
刷刷题刷刷变学霸
举一反三
【单选题】Space is a dangerous place, not only because of meteors (流星) but also because of rays from the sun and other stars. The atmosphere again acts (67) our protective blanket on (68) . Light gets through, ...
A.
from
B.
than
C.
as
D.
away
【单选题】微波是指频率在（ ）范围的无线电波。
A.
100MHz～1000MHz
B.
200MHz～2000MHz
C.
300MHz～3000MHz
D.
300MHz～3000GHz