问题补充:
The effect of the medicine on this kind of disease remains .
A. seen
B. to be seen
C. seeing
D. to see
答案:
A. seen
(答案→)B. to be seen
C. seeing
D. to see
解析:题意为“这种药对这种疾病的效果尚待观察。”由题意可知,remain在此是用作系动词,且see这一动作还没有发生,答案锁定在B和D中间;the effect和see之间是被动关系,所以答案为B。
【标签】非谓语形式作表语