IX. Заполните пропуски предлогами, где это необходимо.

This summer my friend's having a holiday in the country. "There's a river and a wood here," he writes. "I intend to stay here till the end of August or early in September. I'll be back in St. Petersburg at the beginning of September. I'll write to him today if I'm not very busy in the evening. I'm going to write about my work at our Institute."