单选题   His ideas are invariably condemned as ______ by his colleagues.
 
【正确答案】 C
【答案解析】imaginative意为“想象的,虚构的”,ingenious意为“机灵的,有独创性的”,impractical意为“不切实际的”,theoretical意为“理论的”。题干中的谓语condemned“批评,谴责”决定所选词含贬义的感情色彩,故答案为C。