Send a self-addressed envelope for our free catalogue.
Do you recognize the writing on the envelope?
The teacher opened the sealed envelope containing the exam papers.
The pump and seed envelopes are shown multiplied by 10 for clarity.
Initial data collection tools, together with the random allocation, were packaged within sealed, opaque envelopes, each bearing a sequential trial number.
Stationary instrumental groups are placed around the audience and successively play sounds of the same pitch and timbre with similar dynamic envelopes (crescendo-decrescendo).