The science of the library is sometimes broken by a sudden cough or the sound of pages _______.

Time should be made good use of ___ our lessons well.

(2013·山东省胶东示范学校二模)More children in Beijing will reach school age next year, ________ a shortage of primary school teachers in the capital.

It rained heavily in the south,            serious flooding in several provinces.\

  After the teacher called him into the office, the boy admitted _______ in the test.