陆地上一年的降水约（）通过蒸散发返回大气。
A.50％
B.40％
C.66％
D.77％
参考答案：C
______ of the newspapers in the world are written in English. [ ]
A. Three quarter
B. Three fourths
C. Three fourth
D. Third four
苛性化系数是指铝酸钠溶液中氧化铝与苛性碱的分子比。
