Q: Extract the answer to the question from the following context. Question: How can things appear green? Context: Many minerals provide pigments which have been used in green paints and dyes over the centuries. Pigments, in this case, are minerals which reflect the color green, rather that emitting it through luminescent or phosphorescent qualities. The large number of green pigments makes it impossible to mention them all. Among the more notable green minerals, however is the emerald, which is colored green by trace amounts of chromium and sometimes vanadium. Chromium(III) oxide (Cr2O3), is called chrome green, also called viridian or institutional green when used as a pigment. For many years, the source of amazonite's color was a mystery. Widely thought to have been due to copper because copper compounds often have blue and green colors, the blue-green color is likely to be derived from small quantities of lead and water in the feldspar. Copper is the source of the green color in malachite pigments, chemically known as basic copper(II) carbonate.
A: through luminescent or phosphorescent qualities

Q: Extract the answer to the question from the following context. Question: How did the Romans control trade? Context: Notable Greek seafarers include people such as Pytheas of Marseilles, Scylax of Caryanda who sailed to Iberia and beyond, Nearchus, the 6th century merchant and later monk Cosmas Indicopleustes (Cosmas who sailed to India) and the explorer of the Northwestern passage Juan de Fuca. In later times, the Romioi plied the sea-lanes of the Mediterranean and controlled trade until an embargo imposed by the Roman Emperor on trade with the Caliphate opened the door for the later Italian pre-eminence in trade.
A: the sea-lanes

Q: Extract the answer to the question from the following context. Question: What is the highest ISO mentioned? Context: Some high-speed black-and-white films, such as Ilford Delta 3200 and Kodak T-MAX P3200, are marketed with film speeds in excess of their true ISO speed as determined using the ISO testing method. For example, the Ilford product is actually an ISO 1000 film, according to its data sheet. The manufacturers do not indicate that the 3200 number is an ISO rating on their packaging. Kodak and Fuji also marketed E6 films designed for pushing (hence the "P" prefix), such as Ektachrome P800/1600 and Fujichrome P1600, both with a base speed of ISO 400.
A: 3200

Q: Extract the answer to the question from the following context. Question: The earlywood may have wider areas than the latewood in a given ring, but only if what qualification is fulfilled? Context: If there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earlywood or springwood. The outer portion formed later in the season is then known as the latewood or summerwood. However, there are major differences, depending on the kind of wood (see below).
A:
If there are differences