Judging from what has happened here, it’s high time that we _______effective measures to prevent this.

       it rain tomorrow, we would have to call off the hike.

Thank you so much! But for your text message, I ___________ home without my ID card this morning.

It's suggested that some activities ________ to celebrate the 30th anniversary of the Reform and Opening up.

I’m really very busy，otherwise I ________ certainly go there with you.