The scientist ______ much of his time to increasing the rice production.
The town _______ we visited last month is the one _______ the famous painter was born.
By nine o’clock, all the Olympic torch bearers had reached the top of Mount Qomolangma, _______appeared a rare rainbow soon.
Yesterday she sold her car, ______ she bought a month ago.
The Science Museum, ________ we visited during a recent trip to Britain, is one of London’s tourist attractions.
The book was written in 1946, ____ the education system has witnessed great charges.