There are _____advertisements which encourage ______to participate in improving their neighbourhood.

Students build up their vocabularies by         of reading more.

—I’ve got an “A” in the examination. —That’s a good ______. You will surely win a second.

Tom was searching hard in the classroom in the ___ of finding his lost exercise book.

An increasing number of people enjoy sun-bathing, but experts warn that too much ________of the body to strong sunlight is harmful．