下列哪个属于烟草育苗管理时期（）
A、还苗期
B、旺长期
C、十字期
D、成熟
参考答案：C
Jane warns us that our group is going to be very tired and dirty by the afternoon and she is right. However, the evening makes it all ______.
A．favorable
B．worthwhile
C．precious
D．essential
骨骺滋养最重要的血管是（）.
