题目

My challenge for you is this： to read a book for 15minutes every single day for a month．Let me explain a bit， by telling you where the challenge came from． I have many things in common with my dad， like music taste and sense of humor， but sadly reading isn't one of them． I can happily spend a whole day with a book， but my dad can't read a book for longer than about 5 minutes． He reads emails， websites and papers for work， but not books． He's busy， so I think sitting down to read for just 15minutes a day is a good way to relax and to introduce him to reading．My dad i有甲、乙两根外形完全一样的钢棒，一根有磁性，另一根没有磁性，现用甲钢棒的一端接触乙钢棒的中部，发现没有吸引现象，由此可知A.甲钢棒有磁性，乙钢棒没有磁性B.乙钢棒有磁性，甲钢棒没有磁性C.甲、乙钢棒都没有磁性D.无法判断哪根钢棒有磁性