单选题 For a cantilever cast-in-place balcony with a span of 1.5m and a strength of C25, the formwork can be removed when the concrete strength reaches ( ).1.5m，C25，（ ），。

单选题 The main load-bearing structure of the pier abutment is ( ).

单选题 Binding connection is adopted for 8 identical longitudinal steel bars in a beam. The maximum connection joints allowed within a connected section is ( ).8。

单选题 Among the strength grades of masonry mortar, the highest strength is ( ). ，

单选题 The fullness of horizontal mortar joints in brick masonry should be no less than ( ).

单选题 Generally, mixed mortar should be used up within ( ) after mixing.（ ）

单选题 When lifting the columns, the main content of its correction work is ( ). ，

单选题 Which of the following options is not used as a basis for determining the gradient of soil slope? ( )