—The book store ________ a big sale. The books there must be very cheap now.—Sounds great. Let’s go into it and have a look.
I don’t know how ________ commas.
I have trouble ________ the new words.
Miss Li regards all her students _______ her children.
__ is really hard __ them to climb Mount Tai.
If you don't know the word, you can _____ in the dictionary.