Sound speed
Choose the word for each blank.
The speed of sound (otherwise known as Mach 1) varies with temperature. At sea level on a 'standard day', the temperature is 59°F, and Mach 1 is approximately 761 mph. As the altitude increases, the temperature and speed of sound 1 decrease until about 36,000 feet, after which the temperature remains steady until about 60,000 feet. Within that 36,000 – 60,000 foot range, Mach 1 is about 661 mph. Because of the 2 , it is possible for an airplane flying supersonic at high altitude to be slower than a subsonic flight at sea level. The transonic band (the 'sound barrier‘) extends 3 around Mach 0.8 — when the first supersonic shock waves 4 the wing — to Mach 1.2, when the entire wing has gone supersonic .
Options for each gap (alphabetical)
- 1 both · none · not · yet
- 2 variation · variety · ventilation · vibration
- 3 above · beyond · from · towards
- 4 add to · diverge from · from on · prevent from
Opens question #120428 in the RealPTE practice screen.
More Reading & Writing: Fill in the Blanks questions
Reading & Writing: Fill in the Blanks format (Pearson)
Pearson's name: Fill in the Blanks (Dropdown)
| Prompt | Text up to 200 words |
|---|---|
| Time to answer | Not set per question (Part 2 lasts 23–30 minutes) |
| Skills assessed | Reading, Writing |
How it is scored
- Partial credit applies: a partly correct response still scores.
Source: Pearson, PTE Academic & UKVI test format, Part 2: Reading, checked 9 October 2026.