新题做完了，又出现疑惑了。。。

4:In geometry, an ellipse may be defined as the locus of all points,........distances from two fixed points is constant.

A:which as the sum of

Bf the sum which

C:the sum of whose

D:whose sum that the

请问whose为什么会用在这儿呢~？

3:The southwestern (protion) of the United States is a land of (little)rain, and parts of it are (too) dry that (they are) called deserts.

正确的应该是把too改成so吧？那too和so各有什么用法呢？

4:In geometry, an ellipse may be defined as the locus of all points,........distances from two fixed points is constant.

A:which as the sum of

Bf the sum which

C:the sum of whose

D:whose sum that the

请问whose为什么会用在这儿呢~？

1:The United States Constitution provides for a count of the population........a census, every ten years.

A:that it is called

B:when called

C:called

D:as called

请问为什么A不行呢

1:The United States Constitution provides for a count of the population........a census, every ten years.

A:that it is called

B:when called

C:called

D:as called

请问为什么A不行呢