We're conducting a nationwide survey of people's reading habits. Would you have five minutes ________ a few questions?
A:answering
B:to answer
C:to have answered
D:having answered
植物体细胞杂交和动物细胞融合比较,正确的是( )
图例▲的含义是____,图例 的含义是____.
下列红色经典影片都反映了长征的内容,其中体现了红军变被动为主动的首次军事行动的是( )
图,D是△ABC一边BC上一点,连接AD,使△ABC∽△DBA的条件是( )