我需要一勺玉米淀粉来勾芡这道汤。

I need a spoonful of ___cornflour to thicken this soup.

做蛋糕时我用玉米淀粉代替面粉，因为它不含麸质。

I use ___cornflour instead of regular flour when making cakes because it's gluten-free.