【題目】The students played happily at the party last night.

【題目】There are more than three thousand books in the library.

【題目】Although the math problem is a little difficult, I want to work it out alone.

【題目】I think teenagers have the ability to make their own decisions.

【題目】Social workers have opened hotlines to offer free ________ to those in need, especially to the teenagers.

【題目】—It's only 5:00 in the morning. I wonder ________ you get up so early.

【題目】We should help each other.

【題目】Your bike needs ________ at once.

【題目】With the development of technology, smart robots are ________ used in homes and offices.

【題目】Mrs. Black has two dogs. One is big, ________ is small.