全量理论表达了（）与应力之间的关系。
A.局部应变
B.整体应变
C.全量应变
D.单量应变
参考答案：C
化简cos2（π-α）+tan（π+α）cot（-π-α）+sin（2π-α）cos（π+α）tan（2π+α）=______．
Studies show that people are more ______ to suffer from back problems if they always sit before computer screens for long hours.
A．likely
B．possible
C．probable
D．sure
