90+91+92+93+…+99的和为（　　）

根据短文内容判断下列句子正误。

    Wednesday，Sep，28th Today was a sunny day．In the morning，Mike and I went to Bruce's home．It was his Birthday．I bought some pencils with different animals for him．He liked them very much．Mike bought him a pencil-box．Bruce's parents bought him a big cake．After we played the chess，we ate the birthday cake and lunch together．We had a good time．

She____(拥抱)her Mends and then got on the train．

美国在70年代中期发生了经济危机，这场危机主要表现为(      )

①经济停滞     ②工人罢工     ③物价下跌     ④通货膨胀