No. The tank is not large enough to house two female bettas. The basic fish keeping rule is "1 inch of fish needs 1 Gallon of water". A female Betta grows to around 1.5 inches so you would need at least a 3 gallon tank to house the 2 Bettas properly.
Yes with a divider but without they will kill each other.
of course, but only keep one male in there at a time unless you have a divider. They say a one-gallon is big enough but my personal opinion is a 5+
ONLY if they're either two females - or a male * female. Two males housed together WILL fight.
The fish are not bad together. But way to many fish for a ten gallon tank. You put one fish for every gallon. They will probly do fine but you will have to clean more.
NO! you will need at least 5 gallon for those
Absolutely not. One oscar fish needs at least a 75 gallon (US) tank on it's own as they can grow up to a foot in size. If you have already bought the fish, please return it to the store and let them know that you do not have a large enough aquarium for it. You are best to use the 1 gallon bowl as a change bowl, and instead spend a bit of money on a betta tank kit for one betta fish, or 2 if you get one with a divider as they cannot be in the same tank together.
First, buy a 10 gallon glass tank. Second, buy a wire mesh divider at a pet store. Third, install the divider. Fourth, put one gerbil in one side and the other on the other side. Leave them there for about 3 - 4 days. Last, wear rubber gloves and carefully remove the divider, letting them smell each other. If they fight, break them apart and divide them for a couple more days. Repeat until necessary.
Yes.
no
ONLY if they're male and female. If you put two males together - they will fight for dominance, possibly resulting in serious injury to one or both !
yes they can but they have to be in a ten gallon tank or 17 gallon you can fit one inch of a fish per gallon
This is a BIG NO NO!! Bettas need at least 2.5 gallons of water to themselves, and if you put a male and a female together, it will most likely result with you have two dead bettas. Keep your boy and girl in separate 2.5 gallon heated tanks.