About of the earth covered with water,but we have less and less available fresh water.
A.three-fourth;is B.three-fourths;is
C.three-fourth;are D.three-fourths;are
Spacecraft________ made ________ possible for humans to research into the universe.
A.have; it B.has; it C.have; that D.has; that
The Queqiao satellite(卫星)will form a ________ bridge between controllers on the Earth and the far side of the Moon.
A.contribution B.communication C.celebration D.construction
Nick's brother________the navy in 2011and ________the navy since then.
A.joined; has joined B.joined in; has joined in
C.joined in; has been in D.joined; has been in
Be patient! Give him more time，______he will find the answer to the question on his own.
A.but B.or C.and D.so
In front of these houses a river, which is not wide or deep but very clean.
A.stand B.stands C.run D.runs
