根据矫直原理,矫直机的各对矫辊之间应顺着钢材的前进方向逐渐减小。
参考答案:错
--- Have you thought of the topic for the composition?
---Not yet, I _______ it very carefully, but I haven’t decided.
A.will consider
B.have been considering
C.had considered
D.was considering
松针最长的树种是()
A.湿地松
B.黑松
C.白皮松
D.红松