Question: Read this and answer the question

In June 1837 Chopin visited London incognito in the company of the piano manufacturer Camille Pleyel where he played at a musical soirée at the house of English piano maker James Broadwood. On his return to Paris, his association with Sand began in earnest, and by the end of June 1838 they had become lovers. Sand, who was six years older than the composer, and who had had a series of lovers, wrote at this time: "I must say I was confused and amazed at the effect this little creature had on me ... I have still not recovered from my astonishment, and if I were a proud person I should be feeling humiliated at having been carried away ..." The two spent a miserable winter on Majorca (8 November 1838 to 13 February 1839), where, together with Sand's two children, they had journeyed in the hope of improving the health of Chopin and that of Sand's 15-year-old son Maurice, and also to escape the threats of Sand's former lover Félicien Mallefille. After discovering that the couple were not married, the deeply traditional Catholic people of Majorca became inhospitable, making accommodation difficult to find. This compelled the group to take lodgings in a former Carthusian monastery in Valldemossa, which gave little shelter from the cold winter weather.

Where did Chopin and Sand stay in Valldemossa?
Answer: a former Carthusian monastery
Question: Read this and answer the question

Even during the war, Eritrea developed its transportation infrastructure by asphalting new roads, improving its ports, and repairing war-damaged roads and bridges as a part of the Warsay Yika'alo Program. The most significant of these projects was the construction of a coastal highway of more than 500 km connecting Massawa with Asseb, as well as the rehabilitation of the Eritrean Railway. The rail line has been restored between the port of Massawa and the capital Asmara, although services are sporadic. Steam locomotives are sometimes used for groups of enthusiasts.

Under which program did Eritrea develp and repair its transportation infrastructure during the war?
Answer: Warsay Yika'alo
Question: Read this and answer the question

The hole walls for boards with two or more layers can be made conductive and then electroplated with copper to form plated-through holes.  These holes electrically connect the conducting layers of the PCB. For multi-layer boards, those with three layers or more, drilling typically produces a smear of the high temperature decomposition products of bonding agent in the laminate system. Before the holes can be plated through, this smear must be removed by a chemical de-smear process, or by plasma-etch. The de-smear process ensures that a good connection is made to the copper layers when the hole is plated through. On high reliability boards a process called etch-back is performed chemically with a potassium permanganate based etchant or plasma. The etch-back removes resin and the glass fibers so that the copper layers extend into the hole and as the hole is plated become integral with the deposited copper.

What do the hole walls in two-layer PCBs have to be before they can be electroplated?
Answer:
conductive