单选
1. Life is just like a journey with unknown destination, during which people can meet with barriers of all kinds.
A. /; the B. the; I C. an; the D. an; I
2. Children today are still suffering from heavy work at preparing them for the entrance examination to college.
A. aimed B. aiming C. to aim D. aims
3. As a mother, she makes her duty to provide her son with a good education and enable him to find his-feet in a crowd.
A. this B. it C. one D. that
4. The Bird's Nest, design is attractive, is frequently visited by travelers all over the world.
A. whose B. which C. its D. that
5. Experiments in the photography of moving objects____ well in both the United States and Europe before 1900.
A. have been conducting B. were conducting
C. had been conducted D. have conducted
