A number of human foods are dangerous to pets. Many of these foods may seem tasty to our pets but can prove deadly if eaten. It can be very tempting to offer pets food from the table, but pets should not be given human food unless recommended(推荐) by your vet(兽医).
 If you suspect your pet may have eaten a dangerous food, contact your vet immediately. In many cases, early recognition and treatment are critical.
 Grapes and Raisins(葡萄干)
Grapes and raisins can cause sudden kidney(肾) failure in cats and dogs. It is unknown what the toxic agent is in these fruits. However, clinical signs can occur within 24 hours of eating and include vomiting, diarrhea, and lethargy (tiredness). Other signs of illness relate to the eventual shutdown of kidney functioning.
 Garlic and Onions
Garlic(蒜) and onions(洋葱) contain chemicals ________________ red blood cells in cats and dogs. Affected red blood cells can lose their ability to carry oxygen effectively. Cooking these foods does not reduce their potential toxicity(毒性). Fresh, cooked, and/or powdered garlic and/or onions are commonly found in baby food, which is sometimes given to animals when they are sick, so be sure to read food labels carefully.
 Many cases of human food toxicity in pets are accidental. A pet may find and chew on a package of gum or candy, or steal food from a countertop or table. The best way to prevent this is to keep all food items in closed cabinets or in areas that are inaccessible to pets. This may be particularly difficult during the holiday season, when more candy, chocolate, fruit baskets, and other food items are around. Children should also be taught to never give candy, gum, or other human food items to pets.
76. What’s passage mainly about? (within 8 words)
77. Under what condition should you give pets human foods?（within 7 words）
78. Why are grapes and raisins dangerous to pets? (within 10 words)
79. Fill in the blank in paragraph 4. (within 2 words)
80. What are the two key points of helping pets avoid dangerous human foods?
(each within 12 words)
76. (It’s about) Dangerous human foods to pets./ Human foods are dangerous to pets.
77. If (you are) recommended by your vet.
78. Because they may cause kidney failure.
79. that/which damage/affect；damaging/affecting
80. ① To make sure pets can’t find or get the foods.
② To teach children not to feed pets with the foods.