How can you step into the lab with your shoes on? You’re _______ to take them off before you enter it. I told you so!
They were swimming in the river ______ suddenly the storm started.
________ a difficult situation, so you should send a message to him and give some advice to him .
It was dark______ we arrived at the little town .
—Oh, I failed again —Don’t lose heart. One more time, ________ you will succeed.
Mary does every single bit of housework ______her husband Bob just does the dishes at times.