17.What is the main biological function of magnesium in plants?
(A)Potassium can mediate electron transfer
(B) Potassium is an important constituent of amino acids
(C)Potassium is incorporated into chlorophyll and necessary for photosynthesis
(D)Potassium can function as a signal

13.Which form of sulfur can be absorbed by plant leaves?(A)Sulfite(B) Sulfur dioxide(C)Sulfate(D)Methionine

14.Is potassium a mobile element?(A)No, it is not mobile and therefore it is difficult to solubilize for plants(B) Potassium is mobile in acidic soil only(C)Potassium is mobile in soils containing high calcium and aluminum(D)Yes, K is highly mobile in all types of soils

15.What is the main biological function of potassium in plants?(A)Potassium can mediate electron transfer(B) Potassium is an important constituent of amino acids(C)Potassium is an important constituent of sugars(D)Potassium is an essential osmolyte

16.What is the main biological function of iron in plants?(A)Fe can mediate electron transfer(B) Iron is an important constituent of amino acids(C)Fe is an important constituent of sugars(D)Iron is an essential osmolyte

複選題18.Is magnesium highly bioavailable to plants?(A)Magnesium is not very mobile and therefore poorly bioavailable (B) Magnesium easily precipitates and its solubility and bioavailability is low (C)Magnesium is soluble but is easily outcompeted by other elements at acidic pH (D)Magnesium from the atmosphere can easily be absorbed by leaves  

19.Is copper (Cu) an abundant element in plant tissues?(A)Cu does not accumulate in plants tissues because it is highly toxic(B) Cu is an abundant macronutrient in plant leaves(C)Cu is the most abundant of all micronutrients in plant tissues(D)Cu is only abundant in plants growing on alkaline soil

20.Which of these elements are all essential micronutrients?(A)Nitrogen, potassium, phosphorus(B) Magnesium, calcium, sulfur(C)Boron, molybdenum, zinc(D)Silicon, iron, magnesium

1. Which country is not included in the Organization of the Petroleum Exporting Countries (OPEC)? (A) Qatar (B) Iran (C) Libya (D) Venezuela

2. Which of the following statements is most inappropriate? (A) The European Union (EU) was founded in November 1993 in Maastricht (B) The so-call “Breixt” has been scheduled for March 2019 (C) There are democratic and soft-authoritarian regimes in EU member states (D) The newest member state of EU is Croatia

3. Which of the following statements is most inappropriate? (A) The African Union (AU) is an intra-governmental union consisting of 55 countries of Africa (B) The beginning of AU can com from the First Congress of Independence African States in April 1958 in Ghana (C) The highest legislative body of AU is Pan-African Parliament (D) The highest governing body of AU is Executive Council composed by its heads of state or government