【简答题】听力:What did ancient Chinese use kites to do?Q: What did ancient Chinese use kites to do? A.Carry ropes across rivers. B.Measure the speed of wind. C.Pass on secret messages. D.Give warnings of er.
【单选题】On seeing the old lady crossing the road, she ______ her car immediately.
【单选题】_______ , the car stopped all at once. [ ]
A.
Seeing a boy lying on the ground
B.
The minute the driver saw a boy seated on the road
C.
On seeing a boy sitting on the ground
D.
The driver saw a boy standing on the road
【简答题】简述酸雨的形成原因以及影响酸雨形成的主要因素?
【单选题】大多数谷氨酸促代谢型受体激活后可使( )
【单选题】下图是某生态系统的部分物质循环简图,下列叙述正确的是 [ ]
A.
若M为空气中的SO 2 ,造成酸雨的主要原因是②和③过程加剧
B.
若M为空气中的CO 2 ,则C元素在图中①②③④过程中循环形式是CO 2
C.
若M为空气中的N 2 ,则①过程可表示固氮蓝藻的固氮作用;②过程一般不存在
D.
若M为环境中的NH 3 ,则①过程可表示硝化细菌的化能合成作用;②过程表示另一些厌氧型细菌作用