單選題________yearsago,coalcamefromtrees

C解析這里考查學(xué)習(xí)對million，thousand，hundred這類詞的使用。我們知道：“hundred”，“thousand”，“million”它們前面若有數(shù)詞時，它們不能加s，即以單數(shù)形式出現(xiàn)；如果前面沒有任何數(shù)詞，則必須加S，且經(jīng)常與of連用。例如：Millions of people are holding a meeting on the square.幾百萬人在廣場上開會。Five million sets of books are being printed.500萬套書正在付印。Some millions of workers were on strike.好幾百萬人罷了工。Some two million fishes died in the river.大約兩百萬條魚死在河里了。