[Answer] if a mixture is uniform in composition, it is considered to be

Step 1 : Introduction to the question "if a mixture is uniform in composition, it is considered to be"

...If a substance is not chemically pure, it is either a heterogeneous mixture or a homogeneous mixture. If its composition is uniform throughout, it is a homogeneous mixture

[Ans] Which U.S. President once wore a Nazi uniform in a movie?

Step 1 : Introduction to the question "Which U.S. President once wore a Nazi uniform in a movie?"

...of the Third Reich. Reagan, an air force reservist received his call for active service while the film was in production. While Warner's lobbied the government for a 30-day extension, the US Army was only willing to offer two weeks, forcing Reagan to use a double in many scenes