——Who plays the piano , Sam or Jerry?—— Jerry. But he gave the performance chance to Sam this time.
A:well
B:better
C:best
D:the best
13厘米=____分米
27千克=____吨
从绿叶中提取色素,选取的最佳叶片应是
若﹣5xny2与12x3y2m是同类项,则m=____ ,n=____