[单项选择]Not until I had read your letter （） the true state of affairs.
A. I understood
B. I did understand
C. did I understand
D. I understand

[单项选择]It was not until I （　） your letter that I（　） all about the matter.
A. have read; knew
B. would read; had known
C. read; had known
D. had read; knew

[单项选择]It Was not until I had read your last 1etter that l understood the true state Of the sad fortunes Of his family（）
A. 还没读你最后一封信，我就知道了他家遭受的惨况的实际程度。
B. 那是在读完你最后一封信后，我知道了他家的不幸遭遇的实际状况。
C. 我终于读到了你的最后一封信，从信中得知了他家遭受的惨况的实情。
D. 直到读了你最后一封信，我才知道了他家遭受的惨况的实际情形。

[单项选择]It was not until I ______ your letter that I ______ all about the matter.


A. have read; knew
B. would read; had known
C. read; had known
D. had read; knew

[单项选择]

Passage Three
The state of California had to turn off the electricity to almost two million homes and businesses. The state ran out of power.
No one knew when the power would be turned off. People got trapped between floors in an elevator. Firefighters had to save them. These blackouts moved around the San Francisco area. Turning off traffic lights could cause accidents.
Rolling power outages shut down sections of communities across much of northern California, an hour and a half at a time.
People found out it is hard to work without power. Computers don’t work. Locked doors don’t open from a distance.
There has been a power crisis for the past two months. The amount of power isn’t enough to keep up with demand. Debt-ridden utilities couldn’t get suppliers to sell them electricity on credit.
Thursday’s crisis was blamed, in part, on a lack of water for hydropower in the Pacific Northwest.

A. telling people to stop using power
B. loaning the utilities money to buy power
C. buying power and reselling it at low prices to the utilities
D. buying the utilities

[单项选择]Your father had to do all the farm work himself, ______

[单项选择]A state of emergency had been in force since the emperor was overthrown.（　）
A. overtaken
B. overrun
C. overturned
D. overdrawn