In order to meet the deadline, Professor Smith along with his assistants the project day and night.
A．work on B．works at C．is working on D．are working on
Although dragon doesn’t exist, we still take it as a _______ of our nation.
A．example B．sign C．mark D．symbol
Baseball requires teamwork _______ tennis is an individual sport.
A．while B．when C．yet D．although
--- The earthquake last night was really terrible.
--- ______, no people were injured or killed, and they escaped in time.
A．Hopefully B．Luckily C．Sadly D．Unfortunately
Scientists say it may be five or six years _____ it is possible to test this medicine to human patients.
A．since B．after C．before D．when
At last we reached a lonely village, _______ a beautiful river.
A．in front of it lay B．in front of which lay
C．in front of it laid D．in front of which lied
