Boric acid is solid,whereas $BF_3$ is gas at room temperature because of

Identify the correct sets:
$i$. Boron fibres - bullet proof vest
$ii$. Metal borides - protective shields
$iii$. Borax - glass wool
Correct option is

Is boric acid a protic acid? Explain.

$H_3BO_3$ $\xrightarrow{T_1} X$ $\xrightarrow{T_2} Y$ $\xrightarrow{\text{red hot}} B_2O_3$
If $T_1 < T_2$,then $X$ and $Y$ respectively are:

Identify the correct statements about the anomalous behaviour of Boron:
$I$. Boron trihalides can form dimeric structures.
$II$. Boron shows $+1$ as a stable oxidation state.
$III$. Maximum covalency of Boron is four.
$IV$. Boron does not form $BF_{6}^{3-}$ ion.

The total number of acidic oxides from the following list is: $NO$,$N_2O$,$B_2O_3$,$N_2O_5$,$CO$,$SO_3$,$P_4O_{10}$