用狭平板钢板,螺旋卷成并焊接成截面为圆形,外径50em的石油管道
参考答案:25(7305.1900)
_______ exciting news! We will have long _______ holiday after the exam. [ ]
A. What an, a
B. What, a
C. How an, the
D. How, the
山楂的功效是
A.消食化积、行气散瘀
B.消食除胀、降气化痰
C.消食运脾、固精止遗
D.消食健胃、回乳消胀