选出适合句子的单词。

1. Yesterday Xiaoyong ______ (gives/gave) his friend a birthday card.

2. The bovs are ______ (play/playing) football on the playground.

3. My grandma               (was/is) a dancer forty years ago.

4. Did she              (wear/wore) a dress yesterday?

5. He is going to ______ (visits/visit) the London Eye next year.

当被连接的板件受到外力作用时，板件将力传递给铆钉，铆钉所受的剪切和挤压（）。

A、不是同时作用的

B、同时作用在不同的截面和表面上

C、先后作用在对应的表面上

D、先后作用在对应的截面上