6、复习语法:现在进行时、一般现在时、用used to表示一般过去时、现在完成时、一般过去时的被动语态; 学会表达同意和不同意;复习并学会以下基本句型:--We are trying to save the manatees.--Manatees eat about 100 pounds of food a day.--There used to be a lot of manatees.--In 1972, it was discovered that they were endangered.--Some of the swamps have become polluted.在能力