【C9】A．riseB．rangeC．varyD．keep

A． timeB． rangeC． distanceD． space

【C19】A．scopeB．rangeC．fieldD．district

【C4】A．changeB．alterC．varyD．differ

【C10】A．changeB．alterC．varyD．contrast

【C2】A．lengthB．rangeC．extentD．limit

【C9】A．remain stableB．increaseC．keep changingD．decrease