The Salk vaccine is a major factor in the fight to eradicate polio.（）
A. completely destroy
B. carefully disguise
C. sustain
D. contain
查看答案
Although the Carbon 14 method of dating old objects is not foolproof , it is the best method available at present（）
A. wholly operational
B. entirely serviceable
C. fully reliable
D. completely safe
承包单位提请施工组织设计（施工方案）报审时，应满足哪些条件？
微信支付 
支付宝支付