[参考答案]短文题型基础练习 Test 9
61. has been shown
62. more effecitive
63. to blame
64. be required
65. how
66. protecting
67. action
68. /
69. they
70. compared
61. has been shown
62. more effecitive
63. to blame
64. be required
65. how
66. protecting
67. action
68. /
69. they
70. compared
