As a result, they can be made of materials with lower strength-to-weight ratios, such as wood and plastics such as HDPE and PP, although they are also often made with aluminum.
(they; can be made; of materials with lower strength-to-weight ratios, such as wood and plastics such as HDPE and PP) (they; are also made; T:often)
they they
can be made are also made
of materials with lower strength-to-weight ratios, such as wood and plastics such as HDPE and PP
T:often