保险委付必须以（）为前提。
A.实际全损
B.推定全损
C.共同海损
D.单独海损
参考答案：B
I have always been honest and straightforward, and it doesn't matter ________ I'm talking to. [ ]
A. who is it
B. who it is
C. it is who
D. it is whom
一单位从国外购得优质矮牵牛种75g，如栽培条件良好，可有生产多少盆优质盆花？（矮牵牛种子的发芽率为79％，每克种子7000粒，幼苗成品率63％）
