大全531

1.        New techniques in thermal-scanning photography, a process that records radiation from surface areas, makes it possible to study the effects of calefaction, or warming, of a river in greater detail than ever before.

(A) makes it possible to study the effects of calefaction, or warming, of a river in greater detail than ever before

(B) make it possible to study, in greater detail, the effects of calefaction, or warming, of a river than ever before

(C) have made it possible to study in greater detail than ever before the effects of calefaction, or warming, of a river

(D) make possible the study of the effects of calefaction, or warming, of a river in greater detail than it ever was before（C）

(E) has made it more possible than ever before to study in greater detail the effects of calefaction, or warming, of a river

怎么得出的答案？

B 选项表答不清楚.

谓语动词要用复数，所以排除AE,ever before 表明时态要用现在完成时，所以选C