asset
"Capital" can be both singular and plural. When referring to a city that serves as a seat of government, it is singular (e.g., Washington D.C. is the capital of the United States). When referring to financial assets or resources, it is also singular (e.g., they invested their capital in the business).
The singular form of the demonstrative pronoun 'these' is this.
The singular form of "that" is "it."
The singular form is cuff.
it is already in its singular form.
"Stratum" is the singular form of stratum. The plural form is "strata".
The form hypothesis is the singular form. The plural form is hypotheses.
A singular form of dice is a die
The singular form of feet is foot.
The singular form of Oases is, Oasis.
"Wash" is the singular form of "wash."
The singular form of chromosomes is a chromatid.