A:以果蝇作为实验材料
B:运用假说—演绎法进行研究
C:他敢于怀疑,勤奋实践
D:引用荧光标记这一新技术对基因进行定位
John shut everybody out of the kitchen ______ he could prepare his grand surprise for the party.
已知函数f(x)=xx+1,f-1(2)=( )
①8x﹣2=22
②0.4x÷3=1.2
③ 45 x+ 65 x=10.