The prevalent internal cause was existence of the local bacterial source and loss of the resistant ability of wheat varieties, while the decisive factor was the abundant rainfall in spring.
当地菌源的存在和小麦品种的抗性丧失是发生大流行的内因，春季降水量多是大流行的决定性因素。
2
The DFT? Model DLC? is a corrosion resistant, dependable, versatile and economical spring assisted, in-line check valve for a wide range of applications.
抗腐蚀、通用和可靠的弹簧止回阀，经济型、管内螺纹，适用于大部分设备。
3
As alloy additives, ferrosilicon is widely used in low alloy structural steel, alloy structural steel, spring steel, bearing steel, heat - resistant steel and electrical silicon steel.