Above

The plane flies above the mountains continually.
The plane flies above the mountains continuously.
The plane is flying above the mountains today.
The plane flew above the mountains today.
The plane was flying above the mountains today.
The plane was going to fly above the mountains today.
The plane will fly above the mountains today.
The plane will be flying above the mountains today.
The plane is going to fly above the mountains today.

Note: "The plane flies above the moutains today." although the verb is in the present the meaning is in the future.

Vincent Teo wrote:

Can I say, (a) It flies above the mountains all the time in the morning.

You could say: "The plane flies above the mountains all the morning." but it would be a repetitive action rather than something happening in the present.

Vincent Teo wrote:

That mean "today" is doesn't care about the time, right?         That means 'today' has nothing to do with the time, right?   Can I say, (a) It flies above the mountains all the time in the morning. (b) The plane flies above in the sky all the time. (how about "all the time"? Can I use it in present or in past tenses?)   How/What about "all the time" ?  Do you use it in the present (tense) or (in the)past tense?

Vincent Teo wrote:

That mean "today" is doesn't care about the time, right? Can I say, (a) It flies above the mountains all the time in the morning. (b) The plane flies above in the sky all the time. (how about "all the time"? Can I use it in present or in past tenses?)

You can say "the cargo plane flies over the mountain everyday at this time" - this is a general statment describing the action that takes place regularly.

Or- "the cargo plane is flying over the mountain at this time" - the action is taking place now.

Or- "the cargo plane flew over the mountain yesterday at this time"

Or-"the cargo plane has flown  over this mountain everyday at the same time for many years" Something routinely repeated and happened regularly over a period of time.