There are ________ bears on the earth because they have ____________ space on it．

A．fewer and fewer；less and less

B．more and more；fewer and fewer

C．less and less；fewer and fewer

D．more and more；less and less

混凝土浇注时，施工缝应留设在构件承受（）的地方。

A.剪力最大

B.剪力最小

C.弯矩最大

D.弯矩最小