单项选择题 Of the various schemes that have been proposed to model how gene transcription might work in the living body, those involving actual physical contact between enhancers and genes remain________, owing to an absence of direct evidence.

单项选择题 What Spinoza says of laws is equally true of party-platforms―that those are strong which appeal to reason, but________which compel the assent both of reason and the common affections of mankind.

单项选择题 Maureen radiates an unfailing common sense and good humor, although not a false cheery________; she has no illusions about life, and her grace comes from her capability to meet it________.