Listen and read.
[ə]
teach$\textbf{er}$
comput$\textbf{er}$
sharpen$\textbf{er}$
answ$\textbf{er }$
 
[e]
p$\textbf{e}$ncil
d$\textbf{e}$sk
l$\textbf{e}$sson
qu$\textbf{e}$stion
t$\textbf{e}$xtbook
 
[u:]
sch$\textbf{oo}$l
r$\textbf{u}$ler
t$\textbf{wo}$
 
[ʊ]
b$\textbf{oo}$k
textb$\textbf{oo}$k
workb$\textbf{oo}$k
l$\textbf{oo}$k
p$\textbf{u}$t