Oh, you are so clever! You have______ a solution to the difficult problem!

It’s raining heavily outside.- _______, I will go back home because my son has been left alone at home.

Betty is going to London. But I don’t know ________.

We’ll make a trip to Hainan Island next weekend. Will you go with us?—No, I can’t _____ it at present.

Don’t laugh ____ him, he only made a small mistake. [ ]