present perfect and past perfect exercises pdf
TChon 15 PRESENT PERFECT AND PAST SIMPLE TENSE.doc
Ngày tải lên :
08/07/2013, 01:27
... recently, don’t you think?
6 My grandfather died 30 years ago. I (never/meet) him.
4. Fill in the blanks with modals: must - have to - ought to - used to
1. You wash your hands before meals.
2. It’s ... seventeen. In the
play, she must appear in a bright red dress and long black stockings. Last year in another play, she had to
wear short socks and a bright, orange-colored dress. If anyone asks her ... the party?
7. There are many clouds in the sky. It (rain) ….…… ……………………………
6. Read the passage and answer the following questions:
My aunt Nhan is an actress. She must be at least thirty-five....
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Tài liệu Present perfect and past doc
Ngày tải lên :
19/01/2014, 17:20
... has been”)
Vậy thì ai làm nhỉ.
Present perfect and past (2)
Unit 14.
Present perfect and past (2)
A Chúng ta không dùng thì
present perfect (I have done) khi nói về một thời điểm ... quá khứ (
present perfect và past simple) qua các câu sau:
Present perfect (have done)
I’ve done a lot of work today.
Hôm nay tôi đã làm nhiều việc.
Chúng ta dùng thì
present perfect khi ... viết sách).
C Chúng ta dùng thì
present perfect để đưa ra những thông tin mới (xem UNIT 7). Nhưng nếu chúng ta tiếp tục nói về
điều đó, chúng ta dùng thì past simple:
A: Ow! I’ve burnt myself....
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Unit 13. Present perfect and past (1) doc
Ngày tải lên :
22/06/2014, 21:20
... làm nhỉ.
He lost his key (past simple) but now he has found it (
present perfect) .
Anh ấy đã làm mất chìa khóa nhưng bây giờ anh ấy đã tìm ra.
Thì
present perfect là thì hiện tại hoàn ... viết
sách).
C Chúng ta dùng thì
present perfect để đưa ra những thông tin mới (xem UNIT 7). Nhưng nếu
chúng ta tiếp tục nói về điều đó, chúng ta dùng thì past simple:
A: Ow! I’ve burnt myself. ...
They went out after lunch and they’ve just come back. (= they are come back
now).
Sau bữa trưa họ đã đi ra bên ngoài và bây giờ họ vừa quay về.
B Thì
present perfect không được dùng nếu...
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present perfect and present perfect continuous
Ngày tải lên :
02/03/2014, 15:18
... trước đây, hiện tại
anh ta không nhất thiết phải đang ở Hà nội) .
Present Perfect
(Thì Hiện tại hoàn thành)
and
Present Perfect Continuous
(Thì Hiện tại hoàn thành tiếp diễn)
·Dùng với: now ... have written our reports already.
Chúng tôi đã viết xong báo cáo
Present Perfect
Công thức:
Subject + have/has + PP
(PP: past participle – quá khứ phân từ)
trong đó :
Have: dùng với các ngôi: ... tuy không đề cặp nhưng có thể hiểu là anh
ấy vẫn còn tiếp tục dạy)
Các từ hay đi cùng với Present Perfect
Since / for
Already / Not yet
Ever / never
Now that
Dùng để chỉ một hành động...
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Đề tài " Classical and modular approaches to exponential Diophantine equations I. Fibonacci and Lucas perfect powers " pdf
Ngày tải lên :
06/03/2014, 08:21
... and (ii) are treated in Sections 5 and 6, respectively. Sections 7 and
8 are devoted to step (iii). Sections 9 and 10 are concerned with Steps (iv)
and (v). Section 11 deals with steps (vi) and ...
Classical and modular approaches
to exponential Diophantine
equations I. Fibonacci and Lucas
perfect powers
By Yann Bugeaud, Maurice Mignotte, and Samir
Siksek*
CLASSICAL AND MODULAR ... the perfect powers in the Fibonacci
and Lucas sequences naturally reduces to the problem of solving the following
pair of equations:
F
n
= y
p
,n≥ 0, and p prime,(5)
and
L
n
= y
p
,n≥ 0, and...
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Unit 5: Possibility and Probability Perfect Modals pdf
Ngày tải lên :
07/03/2014, 07:20
... has a lot of exams coming up soon, and he is also
working on a term paper. He must have been studying at the library.
Unit 5: Possibility and Probability
Perfect Modals
I. Possibility: May, ... room are turned off. She must be sleeping. (right now).
Past time:
MODAL + have been + v-ing
Meaning: in progress at a time in the past.
ã Ex
1
: Sue wasn’t at home last night when we went ... In negative sentences both must not and don’t have to (also don’t need to and need not) are
used. Must not is used when the speaker expects or orders...
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Sustainable Energy Harvesting Technologies Past Present and Future Part 7 pdf
Ngày tải lên :
19/06/2014, 08:20
... Harvesting Technologies – Past, Present and Future
120
(
)
23
__ _ca cthhsthAlO thCu
TTQR R R=+ + +
(19)
R
th_hs
is the thermal resistance represented by a heat sink and it takes into account ...
relating to the thermal domain and represent heat powers Q
c
at the cold side (15), and Q
h
at
the hot one (16), while the last one comes from the electrical domain and represents an
electrical ... operation and are crucial for
comprehensive understanding of heat to electric energy conversion. After that an
analytical description of the heat flux and power generation in TEMs is presented,...
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Sustainable Energy Harvesting Technologies Past Present and Future Part 9 pdf
Ngày tải lên :
19/06/2014, 08:20
... Circuits and Systems, vol.2, no.4, pp.251-259, 2008.
168
Sustainable Energy Harvesting Technologies – Past, Present and Future
14 Sustainable Energy Harvesting Technologies: Past, Present and Future
At ... Energy Harvesting Technologies – Past, Present and Future
10 Sustainable Energy Harvesting Technologies: Past, Present and Future
4. Hybrid flexible energy harvesting and energy storage
The proposed ... aqueous
156
Sustainable Energy Harvesting Technologies – Past, Present and Future
12 Sustainable Energy Harvesting Technologies: Past, Present and Future
Fig. 13. Voltage across PV panel
Fig. 14....
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Sustainable Energy Harvesting Technologies Past Present and Future Part 14 pdf
Ngày tải lên :
19/06/2014, 08:20
... Harvesting Technologies – Past, Present and Future
254
The transmitter consists of one-chip microcomputer (MCU) PIC16F877A and wireless
module nRF24L01P for the control, and MCU can be connected ... http://www.secomtel.com/UpFilesPDF /PDF/ Agilent /PDF_ DOCS/SKYDIODE/ 03_
SKYDI/HSMS2850 .PDF (Last accessed on 13 July, 2011)
[6] McSpadden, J. et al., H. (1992). Theoretical and Experimental Investigation ... integrated rectenna and DC-DC boost converter
circuits.
1.6.1 DC-DC boost converter design theory and operation
The DC-DC boost converter design theory and actual implementation are presented in...
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