充电时蓄电池有褐色物质自底部上升,电池容量明显不足,是由于()造成的。
A、充、放电电流过大
B、充、放电电流过小
C、极板短路
D、电解液过多
参考答案:A
中度智力低下的IQ为()
A.70~84
B.50~69
C.35~49
D.20~34
E.20以下
II. Choose the correct answers after reading the passage.
1. What did the group do first in the morning? They .
A.went into the forest slowly
B.left the chimp family sleeping in a tree
C.observed the family of chimps wake up
D.helped people understand the behaviour the chimps