伴隨狀況
    在下列表示能力、愿望、傾向等語義的形容詞后邊也要接不定式：able(但其同義詞“ capable”后面要接“of+動名詞”),anxious, eager, glad, inclined(傾向于),liable, likely, pleased, ready等。
    25) Certain [A] minerals are magnetic and are able to detected [B] by instruments that measure [C] differences in the Earth's magnetic fields [D] .