高中英语语法填空

The Black Country is about 10 miles from Birmingham. It’s made up of four districts: Dudley, Walsall, Sandwell, and Wolvehampton.
Historically, it was famous for industry, which explains ___WHY____ 16 the area is called the Black Country. It got its name during the industrial revolution, ____WHEN____ 17 factory pollution turned the local skies black and coal dust from the mines made the soil the same color. Dudley, which is _____PROBABLY_____ 18 (probable) the heart of the Black Country, has a history ____DATING__19 ( date) back over 1,000 years, and its famous castle has been there ____SINCE_____ 20 about the 8th century.
People from Black Country are very friendly. ____BUT_/ HOWEVER___21 their local dialect, which comes from the old “Middle English”, can be very difficult to understand. I still remember taking ___A____ 22 visiting friend from Canada to a local Black Country pub for lunch. _BEFORE_____ 23 the waitress could even finish describing the menu, my friend looked at me with his eyebrows ____RAISED_____ 24 raise）. When I asked what he wanted to order, he just shook his head in disbelief and asked if the waitress whom I______HAD SPOKEN_____ 25 (speak) to just now was naturally speaking English.

My answers：
16-20 why; when; probably; dating; since;
21-25 But, a; Before; raised; spoke

Unexpectedly