选择正确的读音。
粮食____(niáng shi liáng shi) 真____(zhēn zhēng)
乘凉____(chén liáng chéng liáng) 冷____(lěng lěn)
△ABC中,∠C=60°,高BE经过高AD中点F,EF=1,则BF长为( )
63,84,91,53,69,81,61,69,91,78,75,81,80,67,76,81,79,94,61,69,89,70,70,87,81,86,90,88,85,67,71,82,87,75,87,95,53,65,74,77.