用speak，say，tell，talk的适当形式填空。

1. Tom________ he can________ a little Chinese.

2. ―Do you often(经常)________to Kate?

    —No, I don't. I often________ her funny stories.

3. I don't like to________ to Mary.

4. He always________ it.

气体保护焊可以分成（）、（）两大类。