It doesn’t need you to spend much time. It’s just that the time to buy stocks in the evening must be there. At least you must reply to what the teacher said. You don’t need to reply at the time, but you must explain it in advance.
You don't need to spend much time, but the time to buy stocks in the evening must be at least in the teacher's reply, you can not return at that time, but you must explain in advance.<br>
It doesn't need you to spend much time either. It's just that the time to buy stocks at night must be there. What the teacher said must be answered at least. You may not answer at that time, but you must explain it in advance.