Question

小博士：仔細(xì)觀察下面的基數(shù)詞和對應(yīng)的序數(shù)詞的區(qū)別和變化，你會發(fā)現(xiàn)這種變化是有規(guī)律的，你能歸納出來嗎？請根據(jù)規(guī)律填出所缺的基數(shù)詞和序數(shù)詞，并特別注意黑體字的詞。

one	first	eleven	eleventh	twenty-one	twenty-first
two	second	twelve	twelfth	twenty-two	twenty-second
three	third	thirteen	thirteenth	twenty-three	twenty-third
four	fourth	fourteen	fourteenth	twenty-four	______
five	fifth	fifteen	______	twenty-five	twenty-fifth
six	sixth	sixteen	sixteenth	twenty-six	twenty-sixth
seven	______	seventeen	seventeenth	twenty-seven	twenty-seventh
eight	eighth	eighteen	eighteenth	twenty-eight	twenty-eighth
nine	ninth	nineteen	nineteenth	twenty-nine	twenty-ninth
ten	tenth	twenty	twentieth	thirty	thirtieth
thirty-one	thirty-first fortieth ninetieth		hundred	hundredth
forty			thousand	thousandth
ninety			million	millionth

我找到規(guī)律了！請看：

1　　英語序數(shù)詞1～19，除first，second，third等特殊形式外，其余的一般是在相應(yīng)的基數(shù)詞后加-th構(gòu)成。

2　　有幾個序數(shù)詞加-th時拼法不規(guī)則，要注意。如fifth，________ ________ ________。

3　　十位整數(shù)的序數(shù)詞的構(gòu)成方法是先將其基數(shù)詞的詞尾“ty”中的“y”改為“i”，再加“-eth”。如________。

4　　基數(shù)詞“幾十幾”變成序數(shù)詞時，只需將個位數(shù)變成序數(shù)詞，十位數(shù)不變。如________。

Answer 1

答案：

2.ninth,twelfth,eighth

3.thirtieth

4.twenty-eighth