Word Count : 247

---

In underground construction works, proper ventilation is essential to ensure a safe and healthy working environment. Due to the confined nature of underground spaces, natural air circulation is often inadequate, leading to the accumulation of dust, toxic gases, and fumes from __________ _________ _______ ________ ____ _____ _________ ________ ____ ________.
______ _________ ______ ____ __________ ________ ________ ________ _________ ______ ____.
_______ ________ __________ __________ _____ ___ ________ __________ __________.
______ _____ ______ ____ ______ ________ _______ _________ ______ ____ ____.
__________ _________ _______ ____ _______ _______ ____ __________ ______.
________ _________ __________ ____ ___.
_______ _______ _________ _____ _______ ______ __________.
________ _______ ____ _______ ___.
________ ___ _____ ____ ________ __________ _____ ______ _____ ____ ___ _____.
________ ____ ______ ______ _________ ______ ____ _________ _________ _______ _____ ______.
______ ____ _______ __________ ________ __________ _____ ________ ________.
__________ ___ ___ _________ ______ ___ _____ _________ _____ ______ _______ _______.
_________ __________ ____ _______ ______ _______ _____ _________.
_______ _________ _______ _________ ____ _____ _______ _______ __________ _______ _______.
__________ _____ ______ ________ _______ ___ _____ __________.
________ __________ ____ ______ ____ _______.
__________ ___ ____ ________ ______ _______ ___ ____ ___.
___ _______ ________ ______ __________ ________ _____.
________ _____ ____ ____ ____ __________ _________.
__________ ___ _______ ________ ______ __________ _____ _________ _______ ________ ___ ____.
_______ ____ ________ ___ ________.
_________ __________ ___ ____ ______ ________ _________ _________ _________.
____ ________ ____ ________ _____ ____ ___ ____.
______ ________ ___ __________.
Get Full Answer on WhatsApp