Scientists think they have ____ in their attempt to find the causes of some major disease.

9．Not until the third day after the terrible earthquake ______ a phonecall from his mother.

Should it be the first time you ________ money with your dream?[ ]

Every evening after dinner, if not from work, I will spend some time walking my dog.

You know this term is crucial for all of us . For the _____ of entering a good high school , we do should study all day and all night .