图示结构E=常数,在给定荷载作用下若使A支座反力为零,则各杆截面惯性矩的关系应为:()
A.I2=I3
B.I2=4I3
C.I2=2I3
D.I3=4I2
参考答案:D
论述叶燮的诗歌正变论。
根据句意及首字母(汉语)提示,补全单词。
1. The box is e ______. There is nothing in it.
2. My mother asked me to d______ what my new pen-pal was like.
3. Look! The f ______ are working in the fields.
4. Alice and Jim ______ (结婚) in church last week.
5. Be quiet, please. I have good news to ______ (宣布).