Ellen was a painter of birds and of nature,________,for some reason,had withdrawn from all human society.(2012·浙江,17)
The sunlight is white and blinding, ________ hardedged shadows on the ground.
________ with care, one tin will last for six weeks.
Every day ________ a proverb aloud several times until you have it memorized.
All flights ________ owing to the heavy fog, many passengers could do nothing but take trains.
The poem A Red, Red Rose written by Robert Burns is popular with the Chinese young people, because the poem is easy ________.