为了

for; about; in; by; toward; and; so; order; for the sake of; in order to; for the purpose of; so as to; in the interest of; so that

便于

be convenient for; facilitate; make easy; simplify

说明

explain; show; illustrate; clarify; demonstrate; specify; indicate; imply; explicate; signify; lay out; explanation; illustration; clarification; specification; description; instruction; exposition; explication; statement; interpretation; explanatory; illustrative; descriptive