to be very close and spend a lot of time together
非常に近く、共に多くの時間を過ごすこと
"Since childhood, they’ve been joined at the hip."
"子供の頃から、彼らは常に一緒にいた。"
to fail because of trying to do two things at once
to promise solemnly, often in a formal way
to perform extremely well on an exam or task
to watch someone carefully because you don’t trust them comp...
to thoroughly investigate or explore something
to calm down and relax
