高墩爬模爬升时承载体受力处的强度应大于（）。
A.12MPa
B.13MPa
C.14MPa
D.15MPa
参考答案：D
The teachers should teach us ________ our lives _______ hard work, not dreams. [ ]
A. to build; on
B. building; on
C. to build; in
D. build; in
液压泵可将（）能转换成（）能。
