Only recently______to realize the dangers caffeine(咖啡因)might bring to our health. A．that scientists began B．have scientists begun C．scientists have begun D．that did scientists begin
A. A．that B.have C.scientists D.that
【参考答案】
B 本题考查倒装结构，only放在句首要求主谓倒装。题意为，只是最近科学家们才开始认识到咖啡因可能带给我们的危害。