具有遗传易感性的肿瘤是() ["胆囊癌","乳腺癌","胰腺癌","甲状腺癌","脂肪肉瘤"]
当焙烧铸圈的温度升至900℃时,需维持() ["10min","5min","15~20min","1h","2h"]
烘烤铸圈时升温不能过快,从室温升至400℃,升温时间不得低于() ["20min","30min","10min","60min","2h"]
决定反射时间的长短的主要因素是() ["刺激强度的大小","感受器的兴奋性","中枢突触的数目","效应器的兴奋性"]
可燃性气体爆炸极限范围分()和()。
风沙区的防护林体系主要包括()、()、()、()。