防己的横断面显
A.菊花心B.车轮纹C.朱砂点D.大理石样花纹E.云锦纹
参考答案:B
解析:防己的横断面有稀疏的放射状纹理,习称“车轮纹”。故答案选B。
— You speak very good English!
— Thanks. I ______ English in Shandong University for four years.
[ ]
A. study
B. studied
C. was studying
D. had studied
钢筋冷拉应力控制法的实质是()。
A.仅控制冷拉应力
B.控制冷拉应力,又控制冷拉率限值
C.最大冷拉率控制
D.最大应力控制