Critics argue\
Critics may argue\
Many people argue\
One problem with\
Opponents argue that\
Other people argue\
people argue that\
people may argue that\
Proponents argue\
Some argue\
Some argue against\
Some critics argue\
Some may argue\
Some opponents\
Some people argue that\
Some people may argue that\
Some people say\
Some people say that\
on the other hand\
Despite... some argue\
Nevertheless,... some argue\
Opponents of... argue\
Proponents of... may argue\
Even though