Sound travels ______ air ______ a speed of about 340 metres per second.
#47987
A
over; in
B
through; at
C
by; at
D
through; over
推荐题目
— You look happy today.— Yes, the news says the poor children can go to school again ______ the help of ProjectHope.
#48602
A
for
B
at
C
with
D
in
Liu Mei is short. So she sits _______the class.
#50681
A
in the front of
B
in front of
C
in the front
D
behind
