Compared with last year, the output of the factory this year has increased（）20%.

According to the passage, which of the following is true of the last hundred years?

Charging is the filling of the engine cylinder with a supply or charge of fresh air （） compression.

The company posted ______ profits last year because of the aggressive advertising campaign.

For years, doctors _____ millions of patients’ lives with the help of microscopes:

（）is entitled to enter into，with a shipper，any agreement，stipulation，condition，reservation or exception as to the responsibility and liability of the carrier or the ship for the loss of or damage to，or in connection with，the custody and care and handling of the goods prior to the loading on，and subsequent to the discharge from，the ship on which the goods are carried by sea.

According to the passage, residents in the state of Mississippi saved last year from tax breaks about.

Last year was the warmest year on record, with global temperature 0.68 ℃____ the average.

The length of time active immunity lasts varies with different diseases,

The disadvantages of rail compared with motor carrier are（）

The promoters of the Springfield music festival estimated a 50 percent increase in ticket sales from last year, but because of bad weather, ticket sales actually decreased by 25 percent from last year’s level. What percent of the projected ticket sales were the actual ticket sales?

30， What does the writer try to tell us with the last two sentences of the passage?