43. switches
[點(diǎn)撥]空格前是the unseen,可見空格為名詞。前面的句子交代了有些開關(guān)是可見的,有些是不可見的,所以這里應(yīng)該是不可見的開關(guān)switches。
44. We know the train will take one of the tracks leading out, but we have no idea which one
[聽音關(guān)鍵詞]know,train,take tracks,no idea,which one
45. When we think about the future of the universe, we can see our "track" many billions of years into the future
[聽音關(guān)鍵詞]think about,future of universe,see track,billions
46. The goal of science is to reduce the vagueness at the decision points and find the true road that will be followed
[聽音關(guān)鍵詞]goal of science,reduce vagueness,find true road