单项选择题
A.7d B.3d C.1d D.28d
A.(23±3) B.(20±2) C.(20±3) D.(23±2)
A.38%-42% B.36%-40% C.44% D.45%
A.(80±10)mm B.(100±10)mm C.(180±10)mm D.(200±10)mm
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