1)Assume that $E\to M$ is a smooth real vector bundle and $\nabla$ is a connection. (We do not assume any metric compatibility since we do not fix a metric on $E$). Assume that for every vector field $X$ on $M$ with a periodic orbit $\gamma$ and for every $s\in \Gamma^{\infty} (E)$, the section $\nabla_{X}^{s}$ vanish on at laest one point of $\gamma$. Does this implies that $E$ is a (trivial) line bundle? **The motivation:** The Rolle theorem is not valid in dimension greater than one. 2)Let $\ell$ be the canonical line bundle on $\mathbb{C}P^{1}\simeq S^{2}$. $\ell$ is counted as a smooth complex line bundle. Is there a connection $\nabla$ such that for every section $s$ and every periodic orbit $\gamma$ of $X$, the section $\nabla_{X}^{s}$ vanishes on at least one point of $\gamma$? I ask the above question because I search for some unusual diff operator associated with a vector field such that these operators can count the number of attractors of a vector field $X$. As a related post, please see: http://mathoverflow.net/questions/182415/elliptic-operators-corresponds-to-non-vanishing-vector-fields