题型:选择题 — What do you think of your job, Lin Tao? — Wonderful! _____ is an honour to serve the guests from around the world at the Expo. [ ]A. This B. It C. Its D. That 查看答案
题型:选择题 河南的“南阳玉”是中国四大名玉之一,“南阳玉”色泽鲜艳,质地细腻,透明度高。“南阳玉”的主要成分是CaAl2Si2O8。关于CaAl2Si2O8,下列说法正确的是A.CaAl2Si2O8中含有三种金属元素B.CaAl2Si2O8中硅元素的化合价为+4价C.CaAl2Si2O8中钙元素与氧元素质量比为1:8D.CaAl2Si2O8的相对分子质量为162 查看答案