How was your weekend —Great! It was my grandfather’s _________ birthday. We enjoyed ourselves.

This question is very difficult __________ I ask my brother for help.

The Rock & Roll Club was ______ to develop and demonstrate the students’ talent for music. [ ]

Stop ________ about the haze(雾霾）. Just think about what we can do to improve it.

While the National Congress of Communist Party, President Xi instructed the party never to forget we started and then we can accomplish our mission.