Solution:
(a) $\oint_{\vec{E}} \cdot \overrightarrow{d l}=E_{0} h\left[\sin \left(k z_{2}-\omega t\right)-\sin \left(k z_{1}-\omega t\right)\right]$
(b) $\int \vec{B}.{\overrightarrow{d s}} = \frac{\vec{d}_{0} h}{k}\left[\cos \left(k z_{2}-\omega t\right)-\cos \left(k z_{1}-\omega t\right)\right]$