使受冷而变得耐寒

cordoning off───布置警戒线戒严；隔离

handing off───交接

harden off───使受冷而变得耐寒

hardened off───使受冷而变得耐寒

hardening up───使坚硬

hardens off───使受冷而变得耐寒

screening off───挡开；用幕隔开

warding off───避开；挡住

warning off───告诫…离开

These are the seedlings that are hardening off in a hotbed.───这些是放在温床中经受耐寒锻炼的幼苗。

Detailed analysis is made of the reasons why fissures, peeling-off, and tooth breaking exist in the build-up welding layer of cast WC for hardening material of steel-toothed gear drills.───在钢齿牙轮钻头强化材料中，详细地分析了铸造碳化钨堆焊层产生龟裂、脱落和断齿的原因。

Callus was formed and differentiated into numerous rootless plantlets, which were induced to rooting. After hardening off, the rooting plantlets were transplanted to nursery.───愈伤组织继代增殖分化出大量无根小苗，再诱导生根成苗，然后炼苗、田间移栽、成活率达87%。

These are the seedlings that are hardening off in a hotbed.