How to avoid paragraphs get in between figures?

Question

I'm currently facing a problem.

The following paragraph (highlighted) should appear after the figures, why does it shows up between the figures? The enumerate supposed to begin after showing all of the figures.

First page:

Second Page:

\documentclass[manuscript,review,anonymous,article]{acmart} 
\usepackage[export]{adjustbox}
\usepackage{graphicx, float}
\AtBeginDocument{%
  \providecommand\BibTeX{{%
    \normalfont B\kern-0.5em{\scshape i\kern-0.25em b}\kern-0.8em\TeX}}}
\begin{document}
\section{Introduction}
Electromagnetic radiation, in classical physics, the flow of energy at the universal speed of light through free space or through a material medium in the form of the electric and magnetic fields that make up electromagnetic waves such as radio waves, visible light, and gamma rays. In such a wave, time-varying electric and magnetic fields are mutually linked with each other at right angles and perpendicular to the direction of motion. An electromagnetic wave is characterized by its intensity and the frequency of the time variation of the electric and magnetic fields.
Let's have a look at the following figures:
\begin{figure}[ht]
\begin{minipage}[t]{0.45\linewidth}
\centering
\includegraphics[%scale=1
                 width=0.75\linewidth, valign=t]{figures/Picture 1.jpg}
\end{minipage}%
\begin{minipage}[t]{0.55\linewidth}
\textbf{Radio}  \
Collective oscillation of charge carriers in bulk material (plasma oscillation). An example would be the oscillatory travels of the electrons in an antenna.
\end{minipage}
\end{figure}
\begin{figure}[ht]
\begin{minipage}[t]{0.45\linewidth}
\centering
\includegraphics[%scale=1
                 width=0.75\linewidth, valign=t]{figures/Picture 2.jpg}
\end{minipage}%
\begin{minipage}[t]{0.55\linewidth}
\textbf{High-energy gamma rays}  \
Creation of particle-antiparticle pairs. At very high energies a single photon can create a shower of high-energy particles and antiparticles upon interaction with matter.
\end{minipage}
\end{figure}
\begin{figure}[ht]
\begin{minipage}[t]{0.45\linewidth}
\centering
\includegraphics[%scale=1
                 width=0.75\linewidth, valign=t]{figures/Picture 3.jpg}
\end{minipage}%
\begin{minipage}[t]{0.55\linewidth}
\textbf{Touching Night SkiesGamma rays}\
Energetic ejection of core electrons in heavy elements, Compton scattering (for all atomic numbers), excitation of atomic nuclei, including dissociation of nuclei
\end{minipage}
\end{figure}
\begin{figure}[ht]
\begin{minipage}[t]{0.45\linewidth}
\centering
\includegraphics[%scale=1
                 width=0.75\linewidth, valign=t]{figures/Picture 4.jpg}
\end{minipage}%
\begin{minipage}[t]{0.55\linewidth}
\textbf{LEVENSLICHT}\
The new Holocaust monument LEVENSLICHT in collaboration with National Committee for 4 and 5 May remembers the 104,000 Dutch Holocaust victims with 104,000 specially developed luminescent stones, and encourages participation across 170 municipalities. By using invisible ultraviolet light, the specially developed stones with fluorescent pigments can light up every few seconds, like a breath of light.
\end{minipage}
\end{figure}
\begin{figure}[ht]
\begin{minipage}[t]{0.45\linewidth}
\centering
\includegraphics[%scale=1
                 width=0.75\linewidth, valign=t]{figures/Picture 5.jpg}
\end{minipage}%
\begin{minipage}[t]{0.55\linewidth}
\textbf{Reflected IR}\
The next portion of the spectrum of interest is the infrared (IR) region which covers the wavelength range from approximately 0.7 µm to 100 µm - more than 100 times as wide as the visible portion! The infrared region can be divided into two categories based on their radiation properties
\end{minipage}
\end{figure}
\begin{figure}[ht]
\begin{minipage}[t]{0.45\linewidth}
\centering
\includegraphics[%scale=1
                 width=0.75\linewidth, valign=t]{figures/Picture 6.jpg}
\end{minipage}%
\begin{minipage}[t]{0.55\linewidth}
\textbf{Thermal IR}\
Radiation in the reflected IR region is used for remote sensing purposes in ways very similar to radiation in the visible portion. The reflected IR covers wavelengths from approximately 0.7 µm to 3.0 µm. The thermal IR region is quite different than the visible and reflected IR portions, as this energy is essentially the radiation that is emitted from the Earth's surface in the form of heat. The thermal IR covers wavelengths from approximately 3.0 µm to 100 µm.
\end{minipage}
\end{figure}
\begin{enumerate}
    \item For most purposes, the ultraviolet or UV portion of the spectrum has the shortest wavelengths which are practical for remote sensing. This radiation is just beyond the violet portion of the visible wavelengths, hence its name. Some Earth surface materials, primarily rocks and minerals, fluoresce or emit visible light when illuminated by UV radiation.
\item The light which our eyes - our "remote sensors" - can detect is part of the visible spectrum. It is important to recognize how small the visible portion is relative to the rest of the spectrum. There is a lot of radiation around us which is "invisible" to our eyes, but can be detected by other remote sensing instruments and used to our advantage. 

\item Blue, green, and red are the primary colours or wavelengths of the visible spectrum. They are defined as such because no single primary colour can be created from the other two, but all other colours can be formed by combining blue, green, and red in various proportions.

\end{enumerate}
\end{document}
\endinput