  We report multi-wavelength observations of four solar flares on 2014 July 07.
We firstly select these flares according to the soft X-ray (SXR) and extreme
ultraviolet (EUV) emissions recorded by the Extreme Ultraviolet Variability
Experiment and Geostationary Orbiting Environmental Satellites. Then their
locations and geometries are identified from the full-disk images measured by
the Atmospheric Imaging Assembly (AIA), and the time delays among the light
curves in different channels are identified. The electron number densities are
estimated using the Differential Emission Measure method. We find that three of
four flares show strong emissions in SXR channels and high temperature (>6 MK)
EUV wavelengths during the impulsive phase, i.e., AIA 131 A and 94 A, and then
they emit peak radiation subsequently in the middle temperature (~0.6-3 MK) EUV
channels. Moreover, they last for a long time and have smaller electron
densities, which are probably driven by the interaction of hot diffuse flare
loops. Only one flare emits radiation at almost the same time in all the
observed wavelengths, lasts for a relatively short time, and has a larger
electron density. It is also accompanied by a type III radio burst. The bright
emission at the EUV channel could be corresponding to the associated erupting
filament.
