[求助]问道prep题，跪求好心人解答……

Rasiel

141.
            (32450-!-item-!-188;#058&006160)

 

The federal rules aimed at protecting human subjects of medical experiments were established to ensure that patients must be warned of potential risks and an independent panel would evaluate the experiment before it was conducted.

 

(A) must be warned of potential risks and an independent panel would

(B) must be warned of potential risks and that an independent panel

(C) are warned about potential risks and that an independent panel

(D) will be warned about potential risks and an independent panel would

(E) would be warned of potential risks and that an independent panel would

答案是E，想问下B的错误……是不是and后的句型不是非常对称？那如果变成 must be warned of potential risks and that an independent panel must对不对？

还是说用must be语气不对？……

Rasiel

知道了……原来must和ensure语意重复了……让这贴沉了吧……