A.至少為0.65fptk B.至少為0.7fptk C.不超過(guò)0.75fptk D.不超過(guò)0.8fptk
A.45° B.60° C.90° D.135°
A.不受限制B.應(yīng)大于30C.不應(yīng)小于90D.不應(yīng)大于60