正常工作条件下,作用水头相同、面积也相同的的孔口和圆柱形外管嘴,过流能力是否相同? 原因何在?
-Whydidn’tyoutellhimaboutthemeeting?-Herushedoutoftheroom____Icouldsayaword.
A. before
B. until
C. when
D. after
-Whatwasthepartylike?-Wonderful.It’syears____Ienjoyedmyselfsomuch.
A. after
B. before
C. when
D. since