in these circumstances vs under this circumstances

Some examples from the web:

• Dose adjustment is not required in these circumstances.
• The advisability of driving should be considered in these circumstances.
• Consequently the use of INTEGRILIN is not recommended in these circumstances.
• I think that is irrelevant in these circumstances, dear.
• What rehearsal, in these circumstances...
• I will finish here, Madam President, because speaking in these circumstances is rather difficult.
• The advisability of driving should be considered in these circumstances.
• You can't kill a child in these circumstances.
• But I will never risk her life or well-being by revealing that in these circumstances.
• Identification will be difficult in these circumstances, sir.
• Paragraph 58A prohibits the recognition of a gain in these circumstances.
• Paragraph 58A prohibits the recognition of a loss in these circumstances.
• The advisability of driving should be considered in these circumstances.
• It should be considered whether it is advisable to drive or operate machines in these circumstances.
• The advisability of driving should be considered in these circumstances.
• The advisability of driving should be considered in these circumstances.
• It should be considered whether it is advisable to drive or operate machinery in these circumstances.
• Competition does not help in these circumstances.
• Madam President, in these circumstances, I must put to you a personal question.
• This is what has allowed us to unite in these circumstances.

Some examples from the web:

• Everyone who comes in here are under this circumstances.
• Germany correctly pointed out that large companies were also eligible for aid under this scheme under certain circumstances.
• It would be useful here to clarify under which circumstances this does and does not apply.
• Capt Picard, my interpretation of Ventaxian law suggests that under these circumstances this is acceptable.
• Under certain circumstances this funding source can be used for demonstration projects.
• We should not allow this under any circumstances.
• We will not permit this under any circumstances.
• We cannot allow this under any circumstances.
• Under normal circumstances this metal is a liquid with high vapour compressibility.
• We cannot support this under any circumstances.
• Under these circumstances this exporter cannot be considered to have fully cooperated in the investigation.
• Under normal circumstances this would not be a threat to the free market.
• We discovered this island under circumstances that everyone knows.
• And don't leave this room under any circumstance.
• Now, you never use this unless under extreme circumstances.
• You know, Under normal circumstances, This petition would be fairly simple.
• All right, you better start thinking of ways to convince Peter this falls under exigent circumstances.
• Under no circumstances must this right be undermined.
• Under no circumstance should this vaccine be administered by injection.
• Under no circumstance should this vaccine be administered by injection.