人工诱变培育新品种，目前最常用的方法是（）
A.用射线或激光照射
B.花药离体培养
C.秋水仙素处理萌发的种子
D.人工杂交
参考答案：A
区域物流信息服务平台通常包括哪些内容？
A fire must be ventilated（）.
A.when using an indirect attack on the fire such as flooding with water
B.to prevent the gases of combustion from surrounding the firefighters
C.to minimize heat buildup in adjacent compartments
D.if compressed gas cylinders are stowed in the compartment on fire
