【单选题】设 在二阶可导,且 ,则 是 的( ).
【单选题】—What are you going to do this weekend,Mike? —I basketball with my friends. [ ]
【单选题】I like basketball and I often play ______ basketball after school.
【单选题】I am going to play basketball this Saturday_____ I like basketball.
【单选题】设 为偶函数且二阶可导,若 , 则 ( ).
【单选题】某些食品包装袋内有一包物质,用来吸收氧气和水分,以防止食品腐败,常称“双吸剂”.下列物质属于“双吸剂”的是( )
【单选题】设 在二阶可导,且 ,则 是 的( ).