The harder you work at your lessons, the greater progress you ________

The research mainly deals with the difficulty the students have ______ their attention pm their study all the time.

Wang Hui hopes ________ a scientist in the future.

My e-dictionary is nowhere to be found. Who ______have taken it—–Keep looking and you will find it. ________ youhave good luck!

Has your father returned from Europe yet?—Yes, but he ______ here for only three days before his company sent him to America