The archaeologists found gold coins and pottery in the lowest level of the site ________ they reached three months ago.
After the SixParty Talk in Beijing, an agreement was reached _____that North Korea would abandon(放弃)_____ nuclear weapons.
________ his lessons , he failed in the exam.
Maybe you have been to many countries, but nowhere else _______ a more beautiful palace.
This problem may lead to more serious ones if_______ unsolved.
________, you need to give all you have and try your best.