Word Choice

proceed means to move forward; precede means to come or go before

rational, adjective, consistent with or based on reason; rationale, noun, fundamental reason. It was a rational decision to discontinue the study. The rationale for discontinuing the study was the number of patients with serious adverse effects.

sacrifice refers to ritualistic slaughter of animal or human. Killed is preferable

since denotes a relation to time, as in “Since 1967, when x was discovered,...”, and because means “due to the fact that”

use is generally the intended term; utilize suggests the discovery of a new, profitable, or practical use for something; and employ is best reserved for putting a person to work

Use 'whether' when listing alternatives and 'if' when referring to a future possibility.

Clauses including which are nonrestrictive (nonessential) and clauses that include that are restrictive (essential). Nonrestrictive clauses and phrases are set off from the rest of a sentence by a pair of commas or by a single comma if they come at the end of the sentence. For example, “The pen, which was blue, fell off the desk”; here there was only one pen and it was blue and it fell off the desk. Or, “The pen that was blue fell off the desk”; here there were at least two pens, only one of which was blue, and it fell off the desk.

while indicates time and a temporal relationship; whereas, often the word the writer intended, has such meanings as “when in fact”, “that being so”, and “in view of the fact that”