IX. Выберите правильный вариант согласно содержанию текста

1. a) Water often flows into the well along with oil and gas.

b) Drilling mud often flows into the well along with oil and gas.

c) Water often flows in the well along with drilling mud.

2. a) A down-hole perforator uses a perforator to shoot holes through the casing and cement and into the formation.

b) A down-hole perforator uses an explosive to shoot holes through the well and cement and into the formation.

c) A down-hole perforator uses an explosive to shoot holes through the casing and cement and into the formation.

3. a) The drill bit moves at a much faster rate than conventional rotary drilling.

b) The drill bit rotates at a much faster rate than conventional rotary drilling.

c) The drill bit rotates at a lower speed than conventional rotary drilling.