623.The goal _____ providing education for all children ______ 2015 was decided ______ the World Economic Forum in 2000.

A.to;in;at

B.of;at;by

C.of;by;at

D.to;by;for

624.We may be going skiing at Christmas,but it's still all up ______.We'll probably make the decision the day after tomorrow.

A.in the wild

B.in the distance

C.in the air

D.in the long run

623.答案是C;

the goal of…意为:…的目标;by到…时为止；at the World Economic Forum在世界经济论坛大会上。

624.答案是C;

考查介词短语的含义。此处up in the air意为:悬而未决。而in the wild 在野外，在自然环境下；in the distance 在远处；in the long run从长远的角度看。