The pilot lost contact with the military base,______the plane crashed in the desert.

A．that

B．this

C．it

D．on

A．check

B．checking

C．to check

D．checked

A．is

B．are

C．has

D．have

A．did pass

B．pass

C．were to pass

D．had passed

A．circumstances

B．environments

C．situations

D．conditions

A．paused

B．halted

C．ceased

D．cemented

A．without realizing it

B．because it" s part of their religion

C．because superstitions have proven to be true

D．because superstitions are amusing

A．heart

B．stomach

C．head

D．feet

A．safety

B．secret

C．security

D．secrecy

A．at will

B．at random

C．with a hurry

D．at time