It is important that the nighttime sky at an observatory site … free from city lights?

It is important that the nighttime sky at an observatory site … free from city lights?

1. Is
2. Be
3. To
4. That
5. Semua jawaban benar

Jawaban: B. Be.

Dilansir dari ensiklopedia, it is important that the nighttime sky at an observatory site … free from city lights be.