单项选择题
In this paper we develop a model for trajectory planning of air vehicle.
A、A. Explaining the significance or necessity of the research
B、B. Reviewing the existing literature relevant to the present study
C、C. Identifying a gap in the existing literature
D、D. Announcing the purpose/focus of the study
E、E. Outlining the paper structure
In this paper we develop a model for trajectory planning of air vehicle.
A、A. Explaining the significance or necessity of the research
B、B. Reviewing the existing literature relevant to the present study
C、C. Identifying a gap in the existing literature
D、D. Announcing the purpose/focus of the study
E、E. Outlining the paper structure