Key to Pre-unit Test 1
Lesson1　A private conversation—Word order in simple statements
Lesson2　Breakfast of lunch?—The present，simple and continuous
Lesson3　Please send me a card—The simple past
Lesson4　An exciting trip—The simple past and the present perfect
Lesson5　No wrong numbers—The indefinite and definite articles
Lesson6　Percy Buttons—The indefinite and definite articles
Lesson7　Too late—The past continuous
Lesson8　The best and the worst—The comparison of adjectives
Lesson9　A cold welcome—Prepositions of time
Lesson10　Not for jazz—The passive
Lesson11　One good turn deserves another—Review of tenses
Lesson12　Goodbye and good luck—The simple future
Lesson13　The Greenwood Boys—The future continuous
Lesson14　Do you speak English？—The past perfect
Lesson15　Good news—Indirect statements
Lesson16　Apolite request—Type l conditional statements
Lesson17　Always young—Must and Have to
Lesson18　He often does this!—Have(possession/ordinary verb)
Lesson19　Sold out—Can and May
Lesson20　One man in a boat—The gerund after prepositons
Lesson21　Mad or nor—Can and may
Lesson22　Aglass envelope—Verds followed by prepositions：Of，F(xiàn)rom，Inand On
Lesson23　Anew house—Review of tenses，modal and auxilary verds
Lesson24　It could de worse —Special difficulties：Review
Key to Pre-unit Test2
Lesson25　Do the English speak English?—Word order in compound statements
Lesson26　The best art critics—The present，simple and continuous
Lesson27　Awetnight—The simple past
Lesson28　No parking—The simple past
Lesson29　Taxi!—The simple past andthe present perfect simple