preservative，防腐剂，可数
Maple syrup is a natural product containing no preservatives.
alternative（s）to sth某事物的替代，注意用介词to
Maple syrup can serve as a healthy alternative to refined sugar.
moisture水汽，不可数
Maple trees usually grow in areas where there’s plenty of moisture in the soil.
Bore=drill钻vt
In order to make maple syrup, indigenous Indians bored holes in the trunks of maple trees at first and then used containers made of tree bark（不可数）to collect the sap.
Vascular血管的
Oxygen travels around our body through our vascular system.
gritty含沙的
Sugar sand has to be filtered out as it can give the newly-produced maple syrup a gritty taste.
