影响混凝土强度的因素有（）。
A.水泥强度与水灰比
B.集料
C.养护湿度和温度
D.龄期
E.施工方法
参考答案：A, B, C, D
阅读对话，判断正“T”误“F”。
Li Ming: Excuse me. Who's that girl?
Mr. Hu: She's my friend, Paula.
Li Ming: Is she a student?
Mr. Hu: No, she isn't. She is a teacher. She works in a middle school.
Li Ming: Is she an English teacher?
Mr. Hu: Yes, she is.
( ) 1. Paula is Jenny's friend.
( ) 2. Paula is a student.
( ) 3. Paula teaches English.
( ) 4. Paula works in a middle school.
以下哪项不属于船舶保险的保险责任范围？（）
A.火灾
B.爆炸
C.政府征用
D.碰撞
