根据《混凝土结构后锚固技术规程》的规定,()等,均不得作为锚固基材。
A.风化混凝土
B.严重裂损混凝土
C.不密实混凝土
D.结构抹灰层
参考答案:A, B, C, D
树是结点的集合,它的根结点数目是
A.有且只有1个
B.1或多于1个
C.0或1个
D.至少2个
Doing your homework is a sure way to improve your test scores, and this is especially true ____ it comes
to classroom tests.
[ ]
A. since
B. before
C. after
D. when