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- During the tobacco hardening period, bed of tobacco seedling was the falling target of alate aphids, and was the main resource of tobacco virus spread by aphids. 炼苗期烟草苗床是传毒介体有翅蚜着落的靶子中心 ,是烟田蚜传病毒病的主要初侵染源 ,为防治烟草蚜传病毒病的关键时期。
- Harden up a little, we need more speed. 把帆索拉紧一点，我们需要加快速度。
- That period was a bright page in the history of Chinese literature. 那个时期是中国文学史上光辉的一页。
- Let us hope that the period of this injustice will be over soon. 让我们希望这个不公正的时期很快结束吧。
- Hot steel is quenched to harden it. 烧热的钢淬火使它坚硬。
- The varnish takes a few minutes to harden. 清漆几分钟就能变硬。
- Childhood is a period of rapid growth. 幼年是生长迅速的时期。
- He consulted the chronicles of the period. 他参考了这一时期的编年史。
- Don't harden your heart against him. 别对他硬心肠。
- He had to decide within a given period. 他得在一定时间内作出决定。
- She has a detailed knowledge of this period. 她对这段时期的情况了解地相当详细。
- In that period auto sales hit a14-year low. 这时期汽车销售量达到14年来最低水平。
- So we find that hardening operation is made up of heating and quenching. 因此我们发现淬火工序包括加热和淬硬两个步骤。
- In this period, unemployment reaches record levels. 这段时间的失业人数又达到了创纪录水平。
- Which period of history are you studying? 你正在学哪一段历史？
- Please harden in the main ropes, the sail's not tight enough! 请把主要的绳索拉紧些，帆扯得不够紧！
- Anneal means make harden steel soft and remove brittleness. 退火就是使淬火钢变软并消除其脆性。
- Can you tell me the time period when it was stolen? 能不能告诉我大概什么时候被偷的？
- Chaucer wrote in the late mediaeval period. 乔叟写作的时代是中世纪末。
- Able to set and harden under water, as Portland cement. 在水中变硬的能在水下定型并变硬的，如波特兰水泥
