无缝线路实际锁定轨温不在设计锁定轨温范围以内,或左右股长轨条的实际锁定轨温相差超过()时,必须做好放散或调整。
A、5℃
B、10℃
C、15℃
D、20℃
参考答案:A
In agriculture-based countries -- home to 417 million rural people, 170 million of who live on less than $1 a day -- the agricultural sector is essential to overall growth, poverty reduction, and food security. Most of these countries are in Sub-Saharan Africa, where the sector employs 65 percent of the labor force and generates 32 percent of GDP growth.
乳牙的大面积龋坏,不但会使牙弓长度减少,还会影响颌间高度,为确保乳牙正常宽度和高度,对于多个牙面龋坏的牙齿,应该使用()
A.不锈钢合金冠修复牙体
B.远中导板保持器
C.功能性活动保持器
D.局部固定式间隙扩展装置
E.舌弓保持器