[問題]賴水信高分托福文法p302(no.58)

[Katherine]

____a solution to the problem of a future energy shortage, but it also helps to eliminate environmental pollution.
(a)The photovoltaic cell not only provides
(b)Not only does the photovoltaic cell provide
(c)The photovoltaic cell provides not only
(d)Not only the photovoltaic cell provides

答案：B，我選A，請各位大大幫我解答一下，謝謝 ^ ^

[hey]

not only 開頭要倒裝