This is the bag ________ my mother boughtyesterday

The members of the board are discussing the problem right now; it will _____ have been solved by the end of next week

He handed in the essay two days later than hisclassmates，but it was still _____the time limit set bythe teacher

There is“s”in the word “desk”.

In the meeting, the professor expressed his thanks for the aid he _________ from his students