【正文】
right / wrong / unnecessary (3) it is +a +名詞+ to do... It is a pity / a pleasure / a pleasant thing / ones duty / an honor / a shame / a crime / no easy job to do It takes (sb.) some time / courage / patience to do It requires courage / patience / hard work to do *注意: probable 和 possible 均可作表語,但possible可以用不定式作真實主語, 而probable不能用不定式作真實主語。 eg :My idea is to climb the mountain from the north.