Some tourists think that the beauty of mountains is greater than ______ of deserts. A.one B.those C.the one D.that 答案:D 解析: D one可以用来指代前面提到的人或事物,the one特指,均不符合题意。that 可表示上文提到的不可数名词或可数名词的特指,这里that代替的是不可数名词beauty,符合题意;those为复数形式,不合题意。
如图,在正三棱柱ABC-A1B1C1中,E∈BB1,且BE=EB1,求证:截面A1CE⊥侧面ACC1A1.