Introduction

be open to (considerable) debate   be a matter for (ongoing) debate   be the subject of (much) debate   be a basis for (current) debate  

The topic of courses students need to study at school has recently been open to considerable debate. open to debate
...
a matter for debate
...
the subject of debate

think otherwise   share the similar view   take a differing view   hold a different belief  

Although both lines of argument are somewhat justifiable, I think otherwise. think otherwise
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take a differing view
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hold on to a different belief

Body paragraphs (Evaluating ideas)

former   first  first-mentioned   latter  

The former former
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first
...
first-mentioned group defend their argument by stating that history repeats itself over and over.

However,   But then again,   Furthermore,   But even so,  

However, However,
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But then again,
...
But even so, they may have overlooked that such courses might no longer be in demand in today’s market.

doubtless   of course  consequently   indeed  

Of course Of course
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Indeed
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Doubtless the opposite is sometimes true.

that is (to say)   in other word   which means (that)   in other words  

Effective public transit can translate into cleaner environment. That is (to say) That is
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, which means
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In other words, we can preserve the earth for a longer while.

Body paragraph (Presenting personal view)

perspective   standpoint   attitude   point of view/viewpoint  

Looked at from the economic viewpoint, viewpoint
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standpoint
...
perspective investment in space exploration, in turn, can repay the humanity many times.

especially   particularly   obviously   not least  

Advances in technology have facilitated many aspects of our lives, especially , especially
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, particularly
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, not least the system of our communication.

Conclusion

to   in order to   with the intention of   so as to  

Government ought to launch a campaign for promoting new businesses in rural areas to to
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in order to
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so as to draw away the public from the large urban centers.

As a result,   Having said that,   Despite all these,   Be that as it may,  

Having said that, Having said that,
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Despite all these,
...
Be that as it may, it seems to me that the balanced society requires a combination of all fields, as well as freedom of choice in education.