關(guān)于信號(hào)調(diào)制，下述哪種說(shuō)法正確？（）①把調(diào)制信號(hào)控制高頻信號(hào)的過(guò)程叫做調(diào)制；②被調(diào)制的信號(hào)稱(chēng)為載波；③經(jīng)過(guò)調(diào)制后的高頻信號(hào)稱(chēng)為已調(diào)信號(hào)；④從已調(diào)信號(hào)中檢取出原始信號(hào)的過(guò)程稱(chēng)為解調(diào)或者檢波；⑤載波的波長(zhǎng)可以比發(fā)射天線(xiàn)長(zhǎng)許多