The project is based on an agreement, one of _____ purposes is to ensure that the project can be completed before the deadline.

下列加点字，注音完全正确的一项是（ ）

________ the stone in the way. —– Oh, thank you for reminding me.

The river, ________ the banks are covered with trees，is very long

________ Tom ________ Mary speaks good Chinese, sothey can communicate with these Chinese students very well.