Page 95 - ภาษาอังกฤษสำหรับสายวิทยาการอุตุนิยมวิทยา

90

II. SENTENCE PRACTICE: Oral Exercises

NOTE : Sentences about technical information are often composed of two parts: One

part makes a statement; the other part describes a condition that is necessary in

order for the statement to be true.

The front is called warm, or a warm front
(statement) If warm air is replacing cold air (condition)

Sentences of this type may occur with the statement

first followed by the condition, or with the condition first

followed by the statement. Compare the following:

(1) The front is called warm, or a warm front, if warm air is replacing cold air.

(2) If warm air is replacing cold air, the front is called warm, or a warm front.

Statement-condition sentences may use "1f," "when," "as," "since," "whenever," etc.

Direct ions

(1) Look at the phrases given and identify which statement and which is the condition.
(2) Combine the phrases so that the statement is first and say the sentence.

(3) Combine the phrases so that the condition is first and say the sentence.

Example:

Whenever the equilibrium is disturbed (condition) Air begins to flow from areas of higher

pressure to areas of lower pressure (statement)
Say: ’'Air begins to flow from areas of higher pressure to areas of lower pressure whenever

the equilibrium is disturbed."

Say: ''Whenever the equilibrium is disturbed, air begins to flow from areas of higher pressure

to areas of lower pressure.’’