The Zhengguoqu canal was partly responsible for the fact that the Qin state eventually became the first to unify China.

In 1930s, on the ________ of Zhengguoqu Canal, Jinghui Canal was built, which has benefited people living in the Guanzhong Plain up to now.

Due to the high sediment concentration and the broken geological structure of Jinghe riverbed, Zhengguoqu Canal was much silted and became out of use in _______ Dynasty.

After Zhengguoqu Canal was built, large farming lands got irrigated in Guanzhong Plain and became fertile. Since then there were no more disastrous years. Guanzhong Plain became the ________of the State of Qin.