单项选择题Which of the following italicized parts can be ellipted? Don't speak until you are spoken to. A、Don't B、speak C、you are D、speak to
单项选择题人员推销的缺点主要表现为（ ）。 A. 成本低，顾客量大 B. 成本高，顾客量大 C. 成本低，顾客有限 D. 成本高，顾客有限
