Although there is a great number of new books launched onto the market, most of them are merely for the birds.

A. a spate
B. a variety
C. a pile

D. spit

在双底骨架中，纵骨架式和横骨架式的实肋板间距的允许值相比较是（）

A.相同的

B.纵骨架式的大

C.横骨架式的大

D.可按具体情况确定的