第20题: [单项选择]We can infer from the article that in the 1800s England was probably rich in ______. A. wood resources B. technological resources C. natural resources D. coal resources 参考答案:D 答案解析:根据第一段最后一句“Further,emerging scarcity of some technological resource may ignite a re search for,and gr
第29题: [单项选择]熟石膏调拌时的水粉比例为 A. (10~19)ml:100g B. (20~30)ml:100g C. (31~39)ml:100g D. (40~50)ml:100g E. (51~60)ml:100g 参考答案:D 答案解析:[解析] 熟石膏是按(40~50)ml:100g的水粉比例,先将水放入干净的橡皮碗中,然后撒入熟石膏粉,待石膏沉入水中,且表面无多余的水分时,用石膏调刀调和,故本题只能选择D。