How does the physical environment of southeast asia affect human activity?
choose all answers that are correct

1. the cool climate causes monsoon winds to blow across the region, bringing rain for crops
2. the mekong river flows through five mainland countries and has a basin that supports productive agriculture
3. the location and trade activity within the strait of malacca have made singapore an important port
4. both tsunamis and typhoons have caused thousands of deaths over the years