29.【单选题】人们用来测量时间的单位年、月、日等是靠天体在空间中的运动来确定的，测定宇宙天体之间距离的单位是用光在真空中沿直线传播一年的距离（即光年）来衡量的。这说明（）。

Because of this, the economy is ____ to get worse.

The pilot was seriously injured and the ____ would take over.

A ____ of 20,000 people came to the concert.

What＇s the ____ rate between US dollar and Pound?

The customs officer caught a ____ dealer at the airport.

____ is an item that is not legally brought into the country.

She is very ____ and always cares about other people＇s feeling.

The bags are stored in the cargo ____ of the aircraft.

Some airlines provide baby ____ on their international routes.

How many vacant seats are ____ on this flight?