影响混凝土强度的因素有( )。
A.水灰比
B.水泥强度等级
C.外加剂
D.龄期
E.养护温度和湿度
参考答案:A,B,D,E
It is reported that many battles broke out in Middle East. What’s your _____ of the situation there?
A.assessment
B.anxiety
C.comprehension
D.consideration
FTTH接入猫上PON灯不常亮,要检查哪些问题()
A.LOID
B.分光器
C.账号
D.逻辑PON口