有2道英语题目想请教老师.

问题描述:

有2道英语题目想请教老师.
Linda gives a present ____ her mother ____ her birthday.A.to,on B.for,to C.to,to 我觉得用B或者C都不太合适,我想选择A,可是在某人的生日上应该用at 比较确切,
第二题:Paul and Peter's new bicycle is under the tree.(要求一句改为两句)问题是:自行车只有一辆,如果写成:Paul 's new bicycle is under the tree.Peter's new bicycle is under the tree.变成了两辆自行车了.请老师指教.
请老师一定说明理由,

第一题选A,其实to...for也可以
谁说的在生日那天用at?应该用on没错.
第二题
There is a new bicycle under the tree.
The bicycle belongs to Paul and Peter.