根据汉语提示完成英语句子。

1. The movie was too broing.

    I                           (睡着) half way through it.

2. These books will                                           (赠送) to children.

3. The gift he bought is                                            (不够特别).

4. Have you ever                              (听说) the Beijing Speaks English

5. A baby dog is too difficult to                                            (照顾).

6. We should try to                             (取得进步) before the test.

什麽叫信号障碍？主要包括哪些方面？