单项选择题Recent studies show that advertising usually ______ competition and therefore lower prices.
单项选择题Ministers are planning to fund an advertising campaign to ______ the risks of drunk-driving.
单项选择题My grandmother's very ______ now and needs someone at home full-time to look after her.
单项选择题You may never experience an earthquake or a volcanic eruption in your life, but you will ______ changes in the land.
单项选择题Women were also by the constant cycle of pregnancy and childbirth to which they ______ had to resign themselves.