What the doctor really doubts is ______ my mother will recover from the serious disease soon.
Having a trip abroad is certainly good for the old couple, but it remains ______whether they will enjoy it.
The more you practise _____ English, the better your _____ English will be.
The flowers ________ sweet in the garden look ________ and attract the visitors to the beauty of nature.
The possibility of a murder _____, the police have set about looking for the clues to her suicide.
—Mike, our team will play against the Rockets this weekend. I am sure we will win.—______!