问题 单项选择题

在E-R图中,用来表示实体的图形是______。

A.矩形

B.椭圆形

C.菱形

D.三角形

答案

参考答案:A

解析:知识点:实体联系模型及E-R图评析:E-R图中用矩形表示实体集,用椭圆表示属性,用菱形表示联系。

不定项选择
阅读理解

Hamsters are lovely small animals which are similar to mice,and some people 1ike to keep them as pets.They need to eat a balanced diet,or they can become very sick.That’s why hamsters should be fed healthy foods.

Most pet stores sell hamster mix.This is a combination of foods that are just right for hamsters.Some hamsters are picky eaters.They don’t eat anything they don’t like,so you have to find a hamster mix that your hamster will like.Most hamsters only eat a few tablespoons a day.You should feed them at the same time every day,or you can just keep your hamster’s bowl full.Remember to clean the bowl at least once a week.Hamsters also drink a lot of water,so be sure to keep the water supply full and fresh.

Just like people,hamsters like treats.Besides the hamster mix,you can sometimes feed your hamster seeds,nuts,and some other people food.You should never feed your hamster anything unless you are sure that it is safe for hamsters.

Feed your hamster carefully,and always take good care of your pet !

43.If hamsters don’t have a balanced diet,they will         .

A.become sick          B.drink water           C.store food                            D.feel fresh

44.What does the underlined sentence “some hamsters are picky eaters” mean?

A.They pick food with tools.          B.They mix food once a week.

C.They find their food in stores.         D.They only eat the food they like.

45.What’s the passage mainly about?

A.Where to keep hamsters.         B.When to buy hamsters.

C.What to feed hamsters.         D.Why to raise hamsters.