请用所给动词的适当形式填空。

1. We ______________ (have) a picnic tomorrow.

2. My brother ______________ (go) to Xi'an next Sunday.

3. What ______________ you ______________ (do) next weekend?  I______________ (collect) stamps.

4. Where ______________ she ______________ (work) next year?  She ______________ (work) in a

    computer company.

5. What ______________ you going to ______________ (buy) next holiday?  I ______________ (buy) some

    postcards for my friends.

窦性期前收缩有（）

A.提早出现的房性P波

B.提早出现的正常QRS波

C.提早出现的窦性P波

D.提早出现的室性QRS波

E.长间歇后出现的室性QRS波