Write missing symbols, denoted by x,x,x, in the following nuclear reactions: (a) B10(x,α)Be8\mathrm{B}^{10}(x, \alpha) \mathrm{Be}^{8}B10(x,α)Be8 (b) O17(d,n)x\mathrm{O}^{17}(d, n) xO17(d,n)x (c) Na23(p,x)Ne20\mathrm{Na}^{23}(p, x) \mathrm{Ne}^{20}Na23(p,x)Ne20 (d) x(p,n)Ar37x(p, n) \mathrm{Ar}^{37}x(p,n)Ar37.