老师您好,我在做一完形填空时遇到一个选择不清楚。个人觉得好像halfway前面不需要什么词。烦请老师赐教,感谢!
The bear and the monkey wanted to climb up to the tree to pick apples. The monkey quickly climbed up to tree but the bear failed to climb at a time,( ) halfway up the tree.
A. down B.up C. back D.on