The actors have to _____ before they appear in front of the audi

The actors have to _____ before they appear in front of the audience.
A、cover up
B、paint up
C、make up
D、do up
【正确答案】：C
【题目解析】：cover up 掩盖；paint up 装饰； make up 化妆；do up 整理句意; 演员在出现在观众面前之前必须化妆。