Paris is the__________ of France. [ ]
A. city
B. town
C. capital
D. village
答案:C
—Bill, is the pink umbrella Anna's?
—No, it _____ be hers. Hers is purple. [ ]
A. might
B. must
C. can't
铁的某种氧化物里,铁元素和氧元素的质量比是7:3,则铁和氧的原子数比是______,该氧化物中含有铁的质量分数为______.