  This paper is concerned with the inverse acoustic scattering problems of
reconstructing time-dependent multiple point sources and sources on a curve $L$
of the form $\lambda(t)\tau(x)\delta_L(x)$. A direct sampling method with a
novel indicator function is proposed to reconstruct the sources. The sampling
method is easy to implement and low in calculation cost. Based on the sampling
method, numerical algorithms are provided to get the positions and intensities
of the sources. Both theoretical analysis of the indicator function and
numerical experiments are provided to show the effectiveness of the proposed
method.
