4. 熔融金屬液進入模穴時,其流動速度及情形與流路系統設計各部位斷面大小有關,各部位總斷面積的比值,稱為澆口比(Gating ratio)。如下表與圖所示,請計算出澆口比為多少?(請化簡為最簡單整數比),請問此流路設計為增壓還是減壓澆口系統?
註:如圖(六)所示,編號C是包含箭頭所指的兩個流道。
7. The following time series represents sales of imported cars in a city for the years 20I I through 2017:
Suppose we e want to estimate annual sales of imported cars in the year 2018. The expected number of imported
car sales is____________.