28. Dr. Frank failed many times but he finally _____ to find a successful way to solve the problem.
____ I know, many thousands of kids have read the books written by Han Han.
—Have you ever seen ___ book on the desk? —Is it ___ English book? I saw it just now.
—What about the clothes in that shop? —Too bad. I’ll never go there ___.
We can buy things ___ the Internet.
There ___ a foreign concert this evening.