用一副三角尺拼画一个75°的角.
两个阻值相等的电阻串联后的等效电阻是40Ω,那么它们并联后的等效电阻是____ Ω.
Present at the historic meeting ________ many an official on Nov 7, of course President Xi Jinping and Ma Ying-jeou ________.