消化性溃疡病理损伤至少达（） ["黏膜层","黏膜下层","肌层","黏膜肌层","浆膜层"]
昆虫为什么要进行周期性蜕皮？
（）处处与铅垂线垂直。 ["水平面","参考椭球面","铅垂面","大地水准面"]
急性牙髓炎（） ["开髓开放","开髓封失活剂","开髓拔髓开放","麻醉拔髓+根管封药","开髓开放+切开引流"]
细菌耐药最常见的机制是（） ["产生抗生素灭活酶","抗菌药物作用靶位改变","细菌改变代谢途径","细菌细胞膜渗透性改变使抗菌药物不易进入细菌细胞","细菌将抗菌药物排出细菌外"]
简述特定年龄生命表
